Sachin M.-Hands-on CTO & Lead Software Engineer
Check rate
Experience
Chief Technology Officer
Hexis
Hexis is a sports nutrition platform used by 40% of the Tour de France peloton and 50% of the Premier League. I joined as a senior full-stack engineer, moved into the CTO role and still write code most days.
- Helped grow ARR 300%+ and close a $2.1M seed round.
- Rebuilt the core PostgreSQL data model for years of athlete history (millions of rows per table): multi-day queries went from several minutes to under 700ms.
- Athletes in Europe, the US and Australia get a nearby API and a writable PostgreSQL node, kept in sync with pglogical, with automated schema changes.
- Moved the platform from hosted Supabase to Google Cloud (Pulumi), with several dev deploys a day and weekly production releases. Now leading the SOC 2 audit.
- Built the AI behind food logging: athletes snap a meal or say what they ate, and it's matched to real foods and serving sizes.
- Lead a team of four engineers: hiring, code review, mentoring and technical direction. The team builds with Claude Code, Codex and Cursor under shared rules, and AI-written code gets the same review as any other.
Technologies: TypeScript, Node.js, GraphQL, Apollo, Prisma, PostgreSQL, pglogical, Python, React Native, Kafka, Redis/Valkey, Typesense, Pulumi, Google Cloud, Docker, Grafana, Gemini, Claude Code
Lead Software Engineer / Fractional CTO
Toptal
Client engagements through the Toptal network, which accepts the top 3% of freelance talent. Client names withheld under NDA.
- AI startup in financial due diligence, as CTO: built from scratch a platform that reads data rooms page by page and answers analysts with exact page citations. It indexed 10M+ pages and scored 100% on the Vectara RAG benchmark across 3,000 queries. Retrieval is hybrid (vector, BM25, HyDE), and a verification step drops any page that doesn't support the question before an answer is written. Took the company through SOC 2 Type II.
- One of the top 3 stores on Shopify, as lead engineer: internal tools cut the inventory team's workload 30%, and alerts took issue response from days to hours. Built the React Native app on the Storefront GraphQL API and led search, collections and catalog work on Shopify Plus.
- US healthcare company, as lead engineer: owned authentication, payments with reconciliation, and the data layer, all HIPAA-compliant with PHI-safe logging.
- AI virtual try-on platform: a React Native app that stays at 60 FPS while it detects garments on the phone, plus its APIs and developer dashboard. CI/CD cut deploys from days to minutes, with 70%+ test coverage.
Technologies: TypeScript, Node.js, Nest.js, Next.js, React, React Native, Expo, MobX, Python, Go, GraphQL, PostgreSQL, Prisma, TurboPuffer, Redis, Gemini, OpenCV, Firebase, Google Cloud, AWS Serverless, Terraform, Docker, Shopify Plus
Lead Software Engineer
Verizon Media/RYOT
I led a team of 9 engineers (5 backend, 3 frontend, 1 platform) across time zones, building a web-based 3D modeling tool for creators at the NFL, HuffPost and Yahoo.
- Cut deploys from days to minutes, and onboarding from weeks to days with a Docker dev environment.
- Designed the backend from scratch as microservices: AWS Lambda for stateless APIs, Kubernetes (EKS) for long-running processing, and event-driven queues between them, with monitoring throughout.
- Built a pipeline that runs Blender headless to turn huge creator files into versions that render on iOS and Android browsers, with no human in the loop.
- Wrote GraphQL microservices in TypeScript and Go with published documentation, and kept synchronous responses under 300ms.
- Kept test coverage above 70% (Jest, Vitest, k6, Cypress).
Technologies: TypeScript, Go, Node.js, Nest.js, Next.js, React, GraphQL, PostgreSQL, Prisma, DynamoDB, Neo4J, Redis, AWS Lambda, SAM, Kubernetes (EKS), Terraform, Docker, Python, Blender
Senior Software Engineer
ISSUU
- Worked on the OCaml backend serving 100M+ unique users a month.
- Built the next-generation web PDF reader, breaking PDFs down into their basic elements so creators can publish and share content.
- Improved the machine-learning pipeline that extracts articles and their content, cutting the manual work publishers had to do.
- Set coding standards, owned the technical approach across the development life cycle, and onboarded new developers.
Technologies: JavaScript, TypeScript, Node.js, React, Redux, OCaml, Kotlin, Java, Python, Protobuf, D3.js, SQL, RabbitMQ, AWS Serverless, Nginx, Webpack
Senior Software Engineer
Danske Bank
- Built District, a cross-browser banking platform used daily by thousands of business customers, under GDPR and PSD2, with tenant isolation, OAuth 2.0 scopes, encryption and audit logging.
- Wrote the SDK and libraries other teams and outside developers used to build on District, and helped launch its developer marketplace.
- Built real-time financial dashboards with D3.js.
- Implemented API microservices and GoCD pipelines from commit to production, and owned deployments, releases and monitoring (Grafana, AppDynamics, Kibana).
- Interviewed and mentored developers.
Technologies: JavaScript, TypeScript, React, React Native, Cycle.js, Most.js, RxJS, Node.js, D3.js, Java, SQL, RabbitMQ, Nginx, GoCD, Webpack
Software Engineer
K15t Software GmbH
- Performed software development tasks, such as prototyping, feature development, bug fixing, unit testing, and writing automated functional tests.
- Worked on the frontend to efficiently create user interfaces using React and Redux.
- Delivered tech talks to internal and external audiences.
- Helped in recruitment of new hires.
- Developed backend REST APIs using AWS Lambda and Node.js to save costs.
- Technologies: Javascript, Webpack, React.js, Node.js, AWS Serverless
Software Engineer
Brainbuild (Toptal)
- Developed their mobile platform using React Native.
- Implemented a push notifications server for the application.
- Responsible for mobile design and development.
- Technologies: Javascript, Webpack, React Native, Expo.io, Redux, Node.js
Software Engineer
Roomsie (Toptal)
- Developed their web platform using React.
- Developed tooling for other developers to use.
- Developed backend APIs on AWS Lambda to reduce costs.
- Technologies: Javascript, Webpack, React, Expo.io, Redux, Node.js
Lead Software Engineer (Volunteer)
NYC Outward Bound Schools
- Built a dashboard to help manage student data for different user levels using React, Redux, Webpack, and Node.js which saved the company more than $10,000 per year by removing dependency on their old system.
- Created a way to visualize their data to determine key variables to improve student success.
- Engineered a way to upload different types of data and parse them in one single-sourced database.
- Developed a backup and restore system for emergencies.
- Created ways to export data in every possible format.
- Recruited and led four other developers, working remotely.
- Technologies: Javascript, React, Redux, Webpack, Node.js, MongoDB, Bash
Software Engineer
Saferide Health
- Created a notification system for the app dashboard to manage different user notifications.
- Developed a chat system for customer support to help clients make better use of the application.
- Supported the development of the mobile application using React Native and Redux.
- Technologies: React, React Native, Redux, iOS, Javascript
Software Engineer
Freelancing
- One of the top freelancers in my skill set on Upwork.
- Implemented a wide variety of tasks including web scraping, writing small Electron applications, improving mobile apps, developing extensions, frontend, backend, static servers, databases.
- Monitored progress against task estimates to provide status updates to clients and ensure projects stayed on track.
- Planned, documented, and executed plans to ensure all code changes met requirements.
- Worked with various companies ranging from IoT companies to small startups.
- Technologies: Javascript, React, Redux, Webpack, Node.js, Nginx, Ruby, Rails, Java, C++
Industry experience
See where this freelancer has spent most of their professional time.
Experienced in Information Technology, Education, Sport, Banking and Finance, Healthcare, and Media and Entertainment.
Business area experience
See which departments and functions this freelancer has contributed to most.
Experienced in Information Technology and Product Development.
Summary
Hands-on CTO and lead software engineer with 15+ years building products end to end. I still write code most days.
At Hexis, a sports nutrition platform used by 40% of the Tour de France peloton and 50% of the Premier League, I helped grow ARR 300%+ and close a $2.1M seed round. I rebuilt the core data model so multi-day queries went from several minutes to under 700ms, and the platform now runs PostgreSQL in three regions that all take writes.
I also built an AI platform for financial due diligence that indexed 10M+ pages and scored 100% on the Vectara RAG benchmark. Earlier, I led a team of 9 at Verizon Media on a 3D tool used by the NFL, HuffPost and Yahoo, and worked on the ISSUU backend serving 100M+ users a month.
I work in TypeScript, React, React Native, Node.js, Python and Go, with PostgreSQL and Redis on Google Cloud or AWS, and build with LLMs from OpenAI, Anthropic and Google. Algora ranks me in the top 1% of TypeScript engineers, and I have 200+ five-star mentoring reviews on Codementor. Remote, US or EU hours.
Skills
Ai And Llms
- Llm Integration: Openai, Anthropic Claude, Google Gemini
- Rag: Hybrid Search (Vector, Bm25, Hyde), A Verification Step, Page-Level Citations
- Ai Agents And Tool Calling: Mastra, Vercel Ai Sdk, Anthropic Sdk, Mcp Servers
- Document Intelligence And Ocr With Gemini
- Vector Databases: Turbopuffer, Pinecone
- Real-Time Voice Agents: Openai Realtime Over Webrtc
Back End
- Typescript, Node.Js, Nest.Js, Python (Fastapi), Go
- Postgresql: Schema Design, Multi-Region With Pglogical, Prisma, Supabase
- Graphql, Rest, Microservices, Event-Driven Systems
- Redis/Valkey, Kafka, Rabbitmq, Elasticsearch, Typesense, Mongodb, Neo4j, Firebase, Protobuf
Front End And Mobile
- React, Next.Js, React Native, Expo
- Redux, Mobx, D3.Js, Three.Js, Html5, Css, Webpack
- Shopify Plus And The Storefront Api (Headless Commerce)
Cloud And Devops
- Google Cloud; Aws (Lambda, Sam, Eks, Opensearch)
- Pulumi, Terraform, Docker, Kubernetes
- Github Actions, Gocd, Jenkins, Bitbucket Pipelines
- Grafana, Elk, Nginx, Haproxy, Bash
Testing And Practices
- Jest, Vitest, Playwright, Cypress, Appium, K6; 70%+ Test Coverage
- Soc 2, Hipaa, Gdpr, Psd2, Audit Logging
- Team Leadership, Hiring, Code Review, Mentoring
Languages
Education
Bachelor's degree · Computer Science
Statistics
Experience
Global experience
Expertise
Qualifications
Profile
Frequently asked questions
Have questions? Find more information here.
Sachin is based in Póvoa de Santa Iria, Portugal and prefers 100% remote projects.
Sachin speaks the following languages: English (Native).
Sachin has at least 16 years of experience. During this time, Sachin has worked in at least 6 different roles and for 11 different companies. The average length of individual experience is 1 year and 5 months. Note that Sachin may not have shared all experience and actually has more experience.
Based on recent experience, Sachin would be well-suited for roles such as: Chief Technology Officer, Lead Software Engineer / Fractional CTO, Lead Software Engineer.
Sachin's most recent position is Chief Technology Officer at Hexis.
In recent years, Sachin has worked for Hexis, Toptal, and Verizon Media/RYOT.
Sachin is most experienced in industries like Information Technology, Education, and Sport. Sachin also has some experience in Banking and Finance, Media and Entertainment, and Healthcare.
Sachin is most experienced in business areas like Information Technology and Product Development.
Sachin has recently worked in industries like Information Technology, Sport, and Media and Entertainment.
Sachin has recently worked in business areas like Information Technology and Product Development.
Sachin holds a Bachelor in Computer Science.
Sachin is immediately available full-time for suitable projects.
Daily rate distribution
The rates shown represent the typical market range for freelancers in this position based on recent contracts on our platform.
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 14 Oct 2026. Actual rates may vary depending on seniority level, experience, skill specialization, project complexity, and engagement length.
Similar freelancers
Discover other experts with similar qualifications and experience
Kiriakos K.
Hernani C.
Martin D.
Saad K.
Prasad T.
Paul W.
Yannick S.
Gwen G.
Laurin H.
Matthias I.
Experts recently working on similar projects
Freelancers with hands-on experience in comparable project as a Chief Technology Officer
Saqib J.
Ornel Franck W.
Mohamad K.
Stefan A.
Anton P.
Niklas W.
Simona T.
Jürgen F.
Thomas Ü.
Peter S.
Nearby freelancers
Professionals working in or nearby Póvoa de Santa Iria, Portugal
Felix B.
Pedro V.
Ricardo B.
João M.
Tiago G.
Mariana M.
Rajeev K.
Luís P.
Misha G.
Nuno B.
