Node.js Backend Developer (AdTech) at Spalah in Remote

Spalah is a Ukrainian venture builder that connects ambitious tech businesses with the international stage, fostering an ecosystem for rapid growth. We unite visionary founders and diverse talent to create companies that drive global progress.
Our portfolio features over 10 projects spanning Adtech, Martech, Mobile apps, and more.

We’re looking for a Node.js Backend Developer to build and develop AdTech services.
You’ll join our core backend team, led by the CTO — a group of experienced engineers building the infrastructure behind ad delivery and monetization. The team works within a stable business model and has strong expertise in developing scalable, data-driven AdTech platforms.

What you will be doing:
- build and maintain scalable Node.js services (ES6+);
- improve application performance through profiling, optimization, and best practices;
- enhance, refactor, and modernize existing codebases;
- design efficient data models and work with SQL/NoSQL databases, including query optimization and caching;
- write and maintain unit and integration tests, and contribute to high-quality code through code reviews;
- troubleshoot and resolve production issues in Linux environments, ensuring system stability and reliability.

What you bring:

- 1, 5 + years of commercial experience with Node.js;
- solid understanding of asynchronous patterns, the Event Loop, Streams, and garbage collection;
- strong SQL skills (MySQL/PostgreSQL): indexing, query optimization, execution plans, transactions;
- hands-on experience with NoSQL (Redis/MongoDB) and caching strategies;
- confident debugging skills (Node.js debugger) and a solid understanding of HTTP/TCP;
- strong command of Linux CLI and Git;
- clean code approach with a focus on performance and reliability.

Bonus skills:
- AdTech / OpenRTB 2.x/3.x (auctions, bid req/resp, schain, ads.txt/sellers.json);
- ClickHouse, Aerospike, Nginx; parallel/stream data processing;
- experience with high-load/distributed systems; Kafka or RabbitMQ.

What we offer you:
- flexibility and freedom: choose fully remote, hybrid, or office-based work yourself;
- strong team: work alongside some of the industry’s top talent;
- unlimited growth: grow in multiple directions, get freedom to launch your own product;
- career development: take courses, attend top-notch conferences, explore digital library for nonstop growth;
- health support: get medical insurance, paid vacation and sick leaves, and access to a corporate psychologist;
- fun and culture: enjoy off site parties, team-buildings, sport events, and corporate gifts.