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SQL Experts

in minutes from over 15,000 CVs with the power of AI

Hire experts who design queries, tune database performance, and build reliable reporting layers with SQL, PostgreSQL, MySQL, and SQL Server. Get fast, precise matching with vetted, available freelancers.

Meet FRATCH Experts who have recently used SQL

Verified expert

Khalid El Mansouri

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Lead Architect & Developer

Alsbach-Hähnlein
Khalid El Mansouri

Last position:

Lead Architect & Developer at kem-consulting

  • Development of an agent-based governance platform for the automated assurance of EU AI Act compliance and ODA-compliant orchestration of AI services in complex enterprise environments.

  • Design and implementation of an agent-based "Mission Control" framework (Aletheia Conductor) for autonomous state monitoring and process control.

  • Development of "Compliance-as-Code" (CaC) solutions based on OPA/Rego for system-wide enforcement of regulatory guardrails.

  • Integration of TM Forum ODA standards (TMF630, TMF622, TMF642) to ensure interoperability and standardization.

  • Building a highly available event-driven architecture using Redpanda and CloudEvents v1.0 for near-real-time event processing.

  • Implementation of an audit-proof "Evidence Chain" through cryptographic linking of trace logs in preparation for automated audits.

  • Tech Stack: Java 21 (Quarkus Native), TypeScript (Next.js), Redpanda (Kafka API), CloudEvents v1.0, OPA (Open Policy Agent) & Rego, TimescaleDB, ZincSearch, Redis, TM Forum ODA, Git, GitHub, Clean Code Development, Like-C4.

Verified expert

Stefan Ojanen

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AI Product Leader

Berlin
Stefan Ojanen

Last position:

Founder at ProtocolEngine.io

Evidence-led health intelligence platform turning published research into personal health protocols. It scores 430 habits, foods, and supplements against the studies behind them, and moves the score when the evidence moves. Built solo.

  • Built the daily ingestion pipeline across PubMed, bioRxiv, and medRxiv: 43,000+ papers from 3,400+ journals processed into 230,000+ typed evidence claims, each one traceable back to the study it came from.
  • Designed the six-factor evidence scoring model and the public changelog behind it, so no recommendation ever appears without the papers underneath it. 23,000+ grade changes recorded and explained to date.
  • Shipped an entity information model connecting every intervention to its mechanisms, biomarkers, and outcomes: 118 biomarkers with region-specific reference ranges, 77 mechanisms, 32 graded outcomes.
  • Built the personalisation layer: blood panel ingestion that reads lab PDFs with a vision model and corrects results for draw time against the user's wake anchor, plus Oura, WHOOP, and Withings integration for daily readiness context.
  • Operate eleven specialised review agents over the corpus and codebase, covering paper curation, retrieval quality, health-claim compliance across EU and US regimes, and security.
  • Shipped the Evidence Assistant, a RAG assistant that answers from the claim database and cites the underlying papers, plus a B2B practitioner tier, an Expo React Native app, and localisation across 3 languages and 7 markets.

Stack: Next.js 16, TypeScript, Supabase, pgvector, Anthropic Claude, Vercel, DeepInfra.

Verified expert

Onur Kayir

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AI & Automation Consultant · Project Manager for AI Projects

Braunschweig
Onur Kayir

Last position:

Project Manager & Outsourcing Manager at SENEC GmbH (EnBW Group)

  • Setup of a scalable nearshore IT developer hub (Croatia, Czech Republic, Poland) as an independent company through a BOT model (Build – Operate – Transfer)
  • Identification, selection, and management of full-service agencies; introduction of control and governance mechanisms including KPIs, SLAs, and regular service reviews
  • Creation and review of data processing agreements and framework contracts in alignment with Legal & Compliance; integration of regulatory requirements (incl. KRITIS) into process design
  • Consulting on cloud vs. on-premise strategies, data storage, and authorization concepts; support for procurement in vendor selection and provider assessments
  • Change management and process harmonization between internal teams and nearshore partners; reporting to management, CFO, and CIO

Result: Scalable IT developer hub with an audit-proof governance model, reduced operating costs, and faster product development.

Verified expert

Kiriakos Krastillis

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Platform Engineering Tech Lead / Architect

Nickenich
Kiriakos Krastillis

Last position:

Tech Lead / Architect : OTTO API Platform at OTTO

Maturing their API practices on both a business and technology level. My role covers strategy, architecture, developer advocacy as well as hands-on software engineering, enabling both technical teams and business leadership to adopt and act on API-centric principles effectively. Coincidentally, we also establish GitOps, DX and platform best practices with this project.

Highlights:

  • Aligning executives with the initiative by clarifying strategy, replacing misconceptions and myths with facts, clarifying the value of existing assets and enabling informed decision-making
  • Formulating a way forward for API Lifecycle Management at OTTO
  • Driving platform progress and fostering developer engagement by hands-on engineering work towards strategic goals

API Lifecycle Management, Team Topologies, Organizational Evolution, Regulatory, Platform Advocate, Developer Platform, Communities of Practice, Terraform, Kotlin, Kafka, Kong, WSO2, Apigee, Gravitee, Backstage, AsyncAPI, OpenAPI, API Design, AWS, React, Node.js, TypeScript, Redocly, reactive programming, CDC, Golang, Gin, GitOps, DX (developer experience), stakeholder management, roadmaps, workshops, discovery.

Verified expert

Peter Schillen

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Senior AI, Machine Learning & Computer Vision Expert

Mannheim
Peter Schillen

Last position:

Senior ML Engineer & AI Researcher at Anonymous client

Project: Defect generation on inspection images of metal surfaces

  • Environment:* Automated Visual Inspection (AVI), Metallurgy & Manufacturing

  • Goal & implementation: Concept, architecture, and training of Generative Adversarial Networks (Pix2PixHD / SPADE) for image-to-image transformation. Targeted generation of synthetic material defects (e.g. cracks, inclusions, scale) on rough metal surfaces under real inspection-light conditions for privacy-compliant and efficient dataset expansion (Data Augmentation).

  • Technical design: Implementation of robust Generative AI and Computer Vision pipelines in Python and PyTorch. Use of semantic segmentation approaches for mask-guided defect synthesis and downstream evaluation with EfficientDet object detection models.

  • Business impact: Massive dataset upscaling (factor of 10x) without time- and cost-intensive physical inspection runs, while at the same time drastically improving the detection performance of automated inspection systems.

Technologies & skills used: Python | PyTorch | SPADE | Pix2PixHD | EfficientDet | Machine Learning | Semantic Segmentation | Computer Vision

Verified expert

Christian Fritsch

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Architecture Management

Waldesch
Christian Fritsch

Last position:

Architecture Management at Agency

  • Expert in the company's architecture management area

  • Support for standardizing the company's IT landscape

  • Further development of architecture management

  • Shaping the company's business architecture

  • Restructuring, administration and maintenance of all IT assets

  • Support in creating a unified software asset management and CMDB

  • Creation of unified document management (e-file)

  • Transition of documents into a central DMS structure

  • Link between architecture management and the department's internal business process management

  • Support in developing strategic and tactical development plans

  • Organizing communication with key stakeholders

  • Support in the conception, organization and coordination of the architecture office to be built up

  • Accompanying and advising the entire architecture management process

  • Advising the company's business units on architectural topics and their framework conditions

  • MS Office, Windows 10, VBA

  • ITIL, TOGAF, PowerBi, Kanban, Scrum

  • Internal agency tools

  • Open Touch Conversation, Webex, wire, bdbos

  • MS Sharepoint, JIRA, Confluence

  • ARIS, Archimate, BPMN

Verified expert

Tobias Mönch

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Product Owner, Scrum Master, Project Manager

Oebisfelde-Weferlingen
Tobias Mönch

Last position:

Power BI Expert at MID-SIZED RETAIL COMPANY FOR CLEANING TECHNOLOGY AND HYGIENE PRODUCTS

Reporting and controlling with Power BI for a productive ERP system

  • Analysis of ERP data and interfaces for use in Power BI dashboards
  • Evaluation and migration of existing reports (e.g. Excel) to Power BI
  • Development of an access rights concept for selective data access
  • Documentation and training on how to use and adapt the Power BI dashboards

Label: Power BI, Excel, SelectLine ERP, Microsoft SQL, SQL Server Management Studio

Verified expert

Alwin G.

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Head of IT

Essen
Alwin G.

Last position:

IT Interim Manager & AI Strategist

  • AI product development: Design of an AI-supported GRC platform to automate compliance processes.
  • AI expertise: Strategic deepening in Agentic AI and GenAI as a core asset for modern IT governance
  • IT interim management and strategic consulting
Verified expert

Markus Halbedel

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Senior IT Infrastructure, Cloud & Security Consultant

Kaufbeuren
Markus Halbedel

Last position:

Senior M365 Consultant at BITMARCK GmbH

Creation of concepts for M365 implementation, especially Tenants, EntraID, EntraConnect and ExchangeOnline, taking BAS standards into account (mandatory baseline security requirements) in the project "Concept M365" with the aim of transferring the concepts to the M365 environments of Bitmarck and then handing them over to the customer.

  • Creation of a current-state analysis of the existing M365 environments as well as the on-premises environments and the BAS standards.
  • Creation of concepts for the topics Tenants, EntraID, EntraConnect and ExchangeOnline taking the BAS standards into account
  • Design and implementation of an automated solution for creating standardized M365 tenants based on Microsoft M365 DSC (Desired State Configuration)
  • Transfer of the concepts into the M365 environments
  • Creation of detailed technical documentation
Verified expert

Collin Kempkes

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Lead Fullstack Developer

Kempen
Collin Kempkes

Last position:

Software Architect / Fullstack Developer at Equity Bytes

Built an international e-commerce platform for a multi-vendor marketplace for digital assets from scratch. Designed and operated cloud native architectures at enterprise scale.

  • Designed and operated a highly scalable microservice and serverless architecture
  • Built the complete cloud infrastructure with Terraform + AWS CDK in AWS
  • Provisioned ECS/EKS clusters (Fargate), Application Load Balancers (reverse proxy), and Lambda functions
  • Observability & tracing with CloudWatch, DataDog, Prometheus, and Grafana
  • End-to-end setup with DataDog (formerly AWS CloudWatch), Prometheus, and custom Grafana dashboards
  • Integration of advanced metrics (including ORM mapper) and distributed tracing with Jaeger
  • Robust backup and disaster recovery strategies
  • RDS Postgres backups and hourly snapshots
  • Read-only, asynchronously synchronized replicas with automated master failover in emergencies
  • Minute-level rollback capability through versioned Docker images on ECS and Git-based CI/CD pipelines
  • Created CI/CD pipelines with GitHub Actions for automated multi-stage deployments (Dev, Testing, Prod)
  • Integrated Stripe for international payment processing
  • Built a marketplace payment system with multiple parties and payout routines
  • Used Algolia for high-performance real-time search of digital assets on the platform
  • Federation of services with GraphQL and Hasura
  • Later migration to GraphQL Mesh
  • Test Driven Development (TDD) - unit, integration, and E2E testing with Jest, Vitest, and Playwright
  • Used Next.js / React for modern frontend applications in the nx monorepo
  • Enterprise security architecture & access control
  • Integration of JWT tokens with Auth0, OAuth, OIDC, IP guards, BOLA protection, and secret vaults
  • Authorization concepts with RBAC, ABAC, and native Postgres Row-Level Security (RLS)
  • Built internal microfrontends with Retool for fast prototyping and operational business processes

Technologies: ABAC, AWS CDK, AWS CloudWatch, AWS ECS, AWS EKS, AWS Fargate, AWS RDS, AWS S3, Algolia, Auth0, DataDog, Docker, GitHub Actions, Grafana, GraphQL, GraphQL Mesh, Hasura, JWT, Jaeger, Java, JavaScript, Jest, Kotlin, Kubernetes, Monorepo, Next.js, OIDC, Playwright, Postgres, Postgres RLS, Prometheus, RBAC, Redis, Retool, Serverless, Stripe, Terraform, TypeScript, Vitest

Verified expert

Harold Tela

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Senior Software Developer | OOP . Full Stack . Web & Mobile . Cloud-Native

Braunschweig
Harold Tela

Last position:

CPU Watcher — Cloud-Native Monitoring Application at SEUYTEL

  • Planned and developed a CPU monitoring application for monitoring system performance and resource utilization.
  • Designed and implemented a Spring Boot backend providing a REST API for processing and exposing monitoring data.
  • Developed the React frontend for presenting monitoring information in a clear and user-friendly interface.
  • Integrated PostgreSQL for persistent storage and management of application data.
  • Containerized the application and its services using Docker Compose.
  • Automated infrastructure provisioning and deployment using Terraform on AWS.
  • Structured the application as a modern, maintainable system using REST-based communication between frontend and backend.
  • Designed and developed a secure, scalable CPU monitoring architecture (cpu-watcher) with a dedicated collector application that streams monitoring data to the backend, reducing direct exposure of system resources.
  • Designed a secure cloud infrastructure with the database isolated within a private network and OIDC-based authentication.
  • Implemented Infrastructure as Code with Terraform and integrated version-controlled CI/CD pipelines to automate testing, infrastructure changes, and application deployments.
  • Designed and implemented the frontend delivery architecture using AWS CloudFront.

Stack: Spring Boot · React · PostgreSQL · REST API · Docker Compose · Terraform · AWS

Verified expert

Jens Henneberg

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Interim CTO / CDO & Enterprise Architect | AI Compliance & EU AI Act, Azure AI Foundry | Lawyer & Computer Scientist

Wathlingen
Jens Henneberg

Last position:

Interim CTO (occasional assignments) at Fujitsu / FSAS

Stabilizing an Azure/.NET landscape in live operation.

  • Architecture, DevOps, and operational readiness; technical decisions under time pressure
  • Azure DevOps, monitoring, ETL/ELT, cloud security, FinOps, and data-mesh-related topics

Technologies: Azure DevOps, .NET, CI/CD, monitoring, FinOps

Verified expert

Dmitry Pankov

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Freelance Digital Marketing Analyst

Berlin
Dmitry Pankov

Last position:

Freelance Digital Marketing Analyst at Freelance

  • Marketing Strategy: Lead the end-to-end analysis and evaluation of cross-channel marketing campaigns across the entire Customer Journey. My focus is identifying optimization potential and deriving clear, actionable recommendations that drive measurable business impact.
  • Data Science & AI: Advanced predictive modeling (Churn, LTV), market basket analysis, clustering, and real-time AI-powered audience discovery utilizing RAG/LLMs.
  • Marketing Analytics & Measurement: End-to-end attribution analysis, Marketing Mix Modeling (MMM), audience segmentation, conversion path analysis, and A/B testing across all major platforms.
  • Data Engineering & Reporting: Designing and managing robust, multi-platform data pipelines (BigQuery, GCP) for data consolidation, automated dashboard generation, and critical API integrations.
Verified expert

Fadi Shoaa

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AI Engineer | Microsoft Fabric | Data Engineering | Enterprise AI | Document AI

Oberhausen
Fadi Shoaa

Last position:

Development of a production-ready Enterprise Document AI & Recommendation Platform at Freelancer

  • Development of a production-ready Enterprise AI solution for the automated processing of invoices and business documents
  • Integration of Azure AI Document Intelligence and LLM technologies into existing business processes
  • Development of robust REST APIs for automated document processing and system integration
  • Extraction, validation, and storage of structured invoice data in Azure SQL as a base for analytics and machine learning models
  • Development of an AI-based recommendation engine with machine learning and deep learning to generate personalized product recommendations based on historical purchase data
  • Implementation of logging, monitoring, error handling, and validation mechanisms for stable production use
  • Collaboration with business teams to define business rules and integrate the solution into existing enterprise processes

Technologies: Python, Azure AI Document Intelligence, Azure OpenAI, Azure SQL Database, REST APIs, Machine Learning, Deep Learning, OCR, Pandas, JSON, Workflow Automation

Discover over 15,000 top freelancers

Statistics of experts using SQL

Aggregated from the professional profiles of matched freelancers.

Experience

19 years

Position duration

5.1 years

Positions per freelancer

12

Top business areas

Information Technology, Product Development, Project Management

Top industries

Information Technology, Banking and Finance, Manufacturing

Certification focus areas

Information Technology, Project Management, Product Development

Bachelor's degree or higher

90%

Master's degree or higher

60%

Doctorate

9%

Certifications per freelancer

3

Most common languages

German, English, French

Speak two or more languages

97%

Based on our profile pool as of 6 Sep 2026.

Daily rate distribution

0 200 400 600 800
<€400 €400-​800 €800-​1200 €1200-​1600 €1600+

The chart shows how the daily rates of freelancers in this technology are distributed, based on recent contracts on our platform. Each bar covers a rate range — its height shows how many freelancers charge within that range.

Average rates of experts using SQL

Rates are based on recent contracts and do not include FRATCH margin.

800
600
400
200
Rate comparison chart
Daily rate avg. 761 €

The average daily rate is the mean of all daily rates from recent contracts of comparable freelancers on our platform.

800
600
400
200
Rate comparison chart
Median rate 776 €

The median daily rate is the middle value of all daily rates — half of comparable freelancers charge less, half charge more. Unlike the average, it is barely affected by outliers.

Calculated based on our freelancers’ daily rates as of 6 Sep 2026. Actual rates may vary depending on seniority level, experience, skill specialization, project complexity, and engagement length.

About the technology

Core use

SQL is the standard language for working with relational data. Companies use it to query, join, filter, and aggregate information stored in systems like PostgreSQL, MySQL, SQL Server, and Oracle. It sits at the center of reporting, analytics, application back ends, and data pipelines.

Typical work

  • Write and review complex queries
  • Model tables, keys, and relationships
  • Build views, stored procedures, and functions
  • Tune slow queries and indexes
  • Support ETL and reporting logic

Strong SQL work is about more than syntax. Good specialists understand data shape, query plans, transaction behavior, and how different engines handle locking, joins, and indexing. They write code that is correct, maintainable, and fast enough for real workloads.

When to bring in help

Companies usually look for freelance SQL expertise when reporting breaks, queries become hard to maintain, or a migration needs careful handling. It is also common during application launches, dashboard work, data cleanup, and performance troubleshooting. A specialist can step in without long onboarding.

Ecosystem skills

SQL rarely stands alone. Experts often work with database tools, data modeling, BI suites, version control, and backend code that calls into the database. They should also know how to read execution plans, validate constraints, and keep data consistent across changes.

What strong experts do

  • Turn business questions into reliable queries
  • Keep data accurate across inserts, updates, and deletes
  • Improve performance without changing results
  • Document schema decisions clearly
  • Work safely in production-style environments

The best specialists think about how data will be used later, not only how to fetch it today. They spot duplicate records, missing keys, poor indexing, and brittle logic before those issues spread.

Teams and delivery

SQL work fits both remote and on-site collaboration. Remote specialists are often ideal for query reviews, reporting, and tuning tasks, while on-site work can help when a project needs direct access to sensitive systems or close coordination with analysts and internal teams. Clear requirements and sample data make delivery much faster.

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Frequently asked questions

What clients ask us most about SQL — answered in short.

SQL is used to store, query, and transform data in relational databases. Teams rely on it for reporting, dashboards, application logic, data cleanup, and migration work. It is one of the core tools behind day-to-day database operations.

SQL is usually the better fit when data is structured, relationships matter, and consistency is important. NoSQL systems can be useful for flexible schemas or special scale patterns, but they trade away some of the query structure and transactional strength that relational systems provide. Many companies use both, but for business data SQL is often the default choice.

A strong SQL specialist usually knows at least one major engine well, such as PostgreSQL, MySQL, SQL Server, or Oracle. The syntax is similar, but each system has its own functions, indexing behavior, and performance tools. Good specialists understand those differences instead of treating all databases the same.

Besides SQL, useful skills include data modeling, normalization, indexing, query tuning, and basic knowledge of backend systems that read or write the database. For analytics work, familiarity with BI tools and ETL processes helps a lot. For application work, understanding transactions and concurrency is important.

A small reporting fix may need only a specialist who is comfortable with joins, grouping, and views. Larger work such as schema design, performance tuning, or migration planning needs deeper SQL experience and strong judgment about risk. The harder the data quality or production impact, the more important that depth becomes.

Yes, most SQL work can be done remotely because the main deliverables are queries, schemas, scripts, and documentation. On-site collaboration is mainly useful when access is restricted, the data is sensitive, or the team needs close workshop-style sessions. Many companies use a mixed setup with remote execution and direct stakeholder review.

Look at whether the SQL specialist can explain why a query is written a certain way, not just produce a result. Good signs are clean joins, sensible indexing advice, careful handling of nulls and duplicates, and clear communication about trade-offs. Ask for examples of performance fixes, schema changes, or reporting work they have handled.

Yes, SQL remains central even when teams use modern warehouses, transformation tools, or analytics platforms. Many of those tools still depend on SQL for transformations, checks, and reporting logic. If your team works with data, a strong SQL specialist is still highly useful.

The average hourly rate of freelancers who have used SQL in their recent projects is 95 €, which corresponds to a daily rate of about 761 € based on an 8-hour working day.

Of the freelancers who have used SQL in their recent projects, 90% hold at least a Bachelor's degree, 60% hold at least a Master's degree, and 9% hold a doctorate.

On average, freelancers who have used SQL in their recent projects have 19 years of professional experience, with a single engagement typically lasting around 5.1 years.

The most common languages among freelancers who have used SQL in their recent projects are German (98%), English (96%), and French (19%).

The most common industries among freelancers who have used SQL in their recent projects are Information Technology (86%), Banking and Finance (45%), and Manufacturing (41%).

The most common business areas among freelancers who have used SQL in their recent projects are Information Technology (92%), Product Development (75%), and Project Management (60%).

Main locations of FRATCH Experts, who have recently used SQL

Our freelancers and interim experts are at home across the DACH region — available on-site in the major business hubs or fully remote. Choose a location to discover matched specialists, local market insights and up-to-date availability.

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Philipp Thomaschewski

FRATCH CEO

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