Sergej Tissen-Senior IT Consultant
Check rate
Experience
Senior IT Consultant
Freelance
Senior IT Consultant
codecentric AG
- Architecture and development of a serverless-based platform, built serverless AWS infrastructure, continuous deployment pipelines, and implemented business logic. (React, TypeScript, JavaScript, Node.js, AWS, Java, Kotlin, GraphQL)
- Conceived and developed a service to implement requirements from the Digital Supply Act. (Java, Spring Boot, AWS, Kubernetes)
- Advised on architecture and developed a microservices platform for internal business applications. (React, TypeScript, AWS, Java, Spring Boot, Kubernetes)
Senior Fullstack Developer
Jochen Schweizer GmbH
- Migrated and enhanced the e-commerce platform in AWS, set up AWS infrastructure for microservices, continuous deployment pipelines, and designed and implemented microservices.
- Provided organizational and technical mentoring to apprentices.
- Technologies: React, TypeScript, JavaScript, Node.js, AWS, Docker
Scrum Master
Allplan GmbH
- Led teams developing an online project management portal and a CAD application, introduced and scaled Scrum processes to 16 teams.
- Trained and coached on continuous integration adoption.
- Provided organizational and technical mentoring to apprentices.
- Approaches: Scrum, Kanban, DevOps
Technical Project Manager
Aperto AG
- Migrated existing web portals to an enterprise web CMS, coordinated a development team, technical conception and led client workshops.
- Created and monitored project plans, cost estimation, and proposals.
- Technologies: Magnolia CMS (Java), JavaScript
Fullstack Developer
Freelance
- Developed online registration portals for medical conferences. (Java, Groovy, JavaScript)
Fullstack Developer
Lambdalogic GmbH
- Developed online registration portals for medical conferences, backend and frontend development, release management, and designed and implemented a generic form editor. (Java, Groovy, JavaScript)
Fullstack Developer
Alpha-Spirit
- Developed an online e-learning platform for video-based courses. (Java, JavaScript)
Industry experience
See where this freelancer has spent most of their professional time.
Experienced in Information Technology, Professional Services, Healthcare, Tourism, Construction, and Education.
Business area experience
See which departments and functions this freelancer has contributed to most.
Experienced in Information Technology, Product Development, and Project Management.
Summary
Fullstack Developer with 15+ years of experience in software development. Specializing in using React, Next.js, and Java to build efficient and scalable web applications. As a certified AWS Solutions Architect and AWS Developer, I have years of experience implementing cloud-native architectures on AWS. I bring a strong foundation in DevOps practices, utilizing tools such as GitLab and AWS CDK, to create resilient and evolvable solutions.
I am a 🇩🇪 German national, currently freelancing from 🇪🇸 Spain.
Skills
Development
- React
- Typescript
- Javascript
- Node.Js
- Graphql
- Next.Js
- Java
- Spring Boot
OPS
- Ci/Cd
- Docker
- Kubernetes
- Gitlab
- Akamai
- Infrastructure As Code
AWS
- Vpc
- Ecs
- Lambda
- S3
- Dynamodb
- Kinesis
- Route53
- Codepipeline
Architecture
- Serverless
- Microservices
- Cloud-Native
- Event-Driven
- Rest Api Design
Approaches
- Scrum
- Kanban
- Devops
- Lean
- Safe
Languages
Education
IPU Berlin
Bachelor of Arts in Psychology · Psychology · Berlin, Germany · 1.4
University of Paderborn
Bachelor of Computer Science · Computer Science · Paderborn, Germany · 1.6
Certifications & licenses
AWS Certified Developer - Associate Level
IHK Certified Trainer (Trainer Certificate)
Intensive General English Course (6 months in Sydney)
Statistics
Experience
Global experience
Expertise
Qualifications
Profile
Frequently asked questions
Have questions? Find more information here.
Sergej is based in Selva, Spain and can operate in on-site, hybrid, and remote work models.
Sergej speaks the following languages: German (Native), English (Advanced), Russian (Intermediate).
Sergej has at least 18 years of experience. During this time, Sergej has worked in at least 5 different roles and for 7 different companies. The average length of individual experience is 2 years and 4 months. Note that Sergej may not have shared all experience and actually has more experience.
Based on recent experience, Sergej would be well-suited for roles such as: Senior IT Consultant, Senior Fullstack Developer, Scrum Master.
Sergej's most recent position is Senior IT Consultant at Freelance.
In recent years, Sergej has worked for Freelance and codecentric AG.
Sergej is most experienced in industries like Information Technology, Professional Services, and Healthcare. Sergej also has some experience in Tourism, Construction, and Education.
Sergej is most experienced in business areas like Information Technology, Product Development, and Project Management.
Sergej has recently worked in industries like Information Technology and Professional Services.
Sergej has recently worked in business areas like Information Technology and Product Development.
Sergej holds a Bachelor in Psychology from IPU Berlin and a Bachelor in Computer Science from University of Paderborn.
Sergej has 5 certificates. Among them, these include: AWS Certified Developer - Associate Level, AWS Certified Solutions Architect - Associate Level, and IHK Certified Trainer (Trainer Certificate).
The availability of Sergej needs to be confirmed.
Daily rate distribution
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Average rates for similar positions
Rates are based on recent contracts and do not include FRATCH margin.
The average daily rate is the mean of all daily rates from recent contracts of comparable freelancers on our platform.
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.
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