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Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Senior software engineer - **Company:** Syntho - **Location:** Amsterdam, Netherlands - **Experience:** Expert - **Contract:** Permanent contract - **Skills:** Clean Code Principles, JavaScript (Programming Language), Application Layers, Databases, Data Structures, Software Debugging, Software Design Patterns, DevOps, Distributed Computing Environment, Distributed Systems, Django Web Framework, Python (Programming Language), PostgreSQL, Performance Tuning, Software Maintenance, Query Optimization, Queueing Systems, RabbitMQ, Redis, Next.js, Software Engineering, TypeScript, Enterprise Software Applications, ReactJS, Concurrency, Parallel Computation, Technical Debt, Indexer, Backend, Fastapi, Containerization, Integration Tests, Kubernetes, Apache Kafka, Celery, Front End Software Development, Asynchronous Programming, Docker, Web Api - **Published:** August 8, 2026 - **Apply:** https://clk.platform.jobster.com/?at=1786094848&b=&c=df29ac45-dcb8-4fd9-bc87-9df19656aaad&co=bfe17f5c-c663-4546-bded-09f62a429b56&cu=9d19ad1d-25d0-4b84-a20f-8340b86a47b4&cw=7&dt=o&fc=a&gc=a&i=9698d2ee-bc92-42d1-9cc9-408fa7011225&ic=NL&mf=c&p=47b4ebce-5907-42d5-9b5e-b30908a42d08&pm=c&po=5f8e30d1-709e-45e1-83c8-a466772a8ebf&pr=1r&r=https%3A%2F%2Fwww.jobleads.com%2Fregistration%2Fjob%3FcampaignId%3D118%26jmId%3D2377%26jobId%3Deeb0ebf6cde5b7448978ed9640931db86%26jobLocation%3D1869045806%26utm_campaign%3Djobs%26utm_content%3Djobmarket-id%253D2377%257Clandingpage-id%253Dn%252Fa%257Cjob-id%253Deb0ebf6cde5b7448978ed9640931db86%257Cjob-workarea%253D08-08%257Cjob-hierarchy%253D4%257Cjob-salary-benchmark%253D3%257Cjob-industry%253D%257Cjob-location%253Damsterdam%257Cjobtitle%253Dsenior-software-engineer%26utm_medium%3Djob-external%26utm_source%3Djobster%257Cr-jb%257C__Liplyn%2BIG__%257Cc-nl&s=mp&t=cl&u=ip-c96c6b498870b75e67af1437c04c5e8c&v=d49addb4-a03f-4536-b417-c9600df76b11&sig=6f3e5e6b5b3a22d1588f380d4e3aa5af30c10e1df5e3289f0145974a ## About the Role * Strong knowledge of computer science fundamentals, including algorithms, data structures, concurrency, and distributed computing. * Proficiency in Python for backend development. * Experience with FastAPI and Django (authentication & authorization). * Proficiency in JavaScript/TypeScript, particularly with ReactJS and Next.js. * Strong experience with databases and PostgreSQL, including query optimization. * Familiarity with Ray.io or similar distributed computing frameworks. * Solid understanding of asynchronous programming and parallel processing. * Experience in designing scalable and maintainable software architectures. * Strong problem-solving skills and ability to work on complex technical challenges. * Excellent communication and collaboration skills. * Experience refactoring large-scale applications and resolving performance bottlenecks. * Knowledge of containerization (Docker, Kubernetes). * Experience with CI/CD pipelines and DevOps practices., * Familiarity with message queues such as Redis, RabbitMQ, Kafka. * Experience leading engineering teams or mentoring junior developers. ## Description We are looking for a Senior Software Engineer to join our team and help improve our rapidly growing application. You will work across all layers of our technology stack, solving complex challenges related to distributed computing, performance optimization, and software maintainability. Your contributions will directly impact the scalability, reliability, and efficiency of our platform., * Design, develop, and optimize both frontend and backend components, ensuring clean, maintainable, and efficient code. * Capable of developing production-ready features from front to back. * Address technical debt, refactor inefficient code, and resolve memory overflow issues. * Implement software engineering best practices (SOLID, DRY, Clean Code, Design Patterns, etc.). * Write and maintain unit and integration tests for all application layers. * Improve system observability, monitoring, and debugging tools. * Collaborate with other engineers and stakeholders to define best practices and architectural improvements. * Our technology stack consists of Ray.io, FastAPI, Celery/Redis, Alembic, Django (being discontinued), and NextJs; the person for this position should be capable of engineering solutions using this technology stack with least friction, or in similar ones. * Usual tasks to be performed within the technology stack: + Enhance and maintain our FastAPI-based web API and help discontinue our Django authentication and authorization layer by adding this support to FastAPI itself. + Improve and extend our Next.js/ReactJS frontend, ensuring a smooth user experience. + Work with Ray.io to optimize and scale our distributed computing tasks. + Optimize PostgreSQL database queries and indexing for high performance. ## Related Videos - [Celery on AWS ECS - the art of background tasks & continuous deployment](https://www.wearedevelopers.com/videos/561-celery-on-aws-ecs-the-art-of-background-tasks-continuous-deployment) - [Docker Compose: Rediscovered](https://www.wearedevelopers.com/videos/1978-docker-compose-rediscovered) - [Reducing LLM Calls with Vector Search Patterns - Raphael De Lio (Redis)](https://www.wearedevelopers.com/videos/1714-reducing-llm-calls-with-vector-search-patterns-raphael-de-lio-redis) - [Build and Deploy a Fullstack App with Open Source Tooling](https://www.wearedevelopers.com/videos/775-build-and-deploy-a-fullstack-app-with-open-source-tooling) - [Walking into the era of Supply Chain Risks](https://www.wearedevelopers.com/videos/376-walking-into-the-era-of-supply-chain-risks) - [Docker build without Docker](https://www.wearedevelopers.com/videos/100114-docker-build-without-docker) ## Related Articles - [Dev Digest 120 - Apple and peers](https://www.wearedevelopers.com/magazine/455-dev-digest-120-apple-and-peers) - [Software Developer Salary in The Netherlands [2023]](https://www.wearedevelopers.com/magazine/217-software-developer-salary-in-the-netherlands-2023) - [Dev Digest 121 - AI goes offline](https://www.wearedevelopers.com/magazine/456-dev-digest-121-ai-goes-offline) - [The 7 Most Popular Backend Frameworks for Developers](https://www.wearedevelopers.com/magazine/403-the-7-most-popular-backend-frameworks-for-developers) - [Why Upskilling And Reskilling is Important For Developers](https://www.wearedevelopers.com/magazine/428-why-upskilling-and-reskilling-is-important-for-developers) - [How to Find Tech Jobs in Amsterdam](https://www.wearedevelopers.com/magazine/279-how-to-find-tech-jobs-in-amsterdam)