2026 —
Senior Back-End Developer
Automotive technology
Backend systems for a consumer platform serving millions of users, with a focus on keeping it fast and reliable under continuous real-time load.
Senior Software Engineer
Arnas Grigaliūnas
I have spent a decade building backend systems — designing APIs, integrating services that were never meant to talk to each other, and keeping all of it fast and secure under real load — most recently on systems serving millions of users.
That work has spanned investor relations, healthcare, sports, e-commerce and proxy infrastructure — different domains, the same underlying problem of making systems talk to each other reliably. I work across the whole path to production: API design, data modelling, frontend where it is needed, infrastructure and deployment. If you need one engineer who can own a piece end to end rather than a slice of it, that is the kind of work I do.
01
Experience
2024 — 2026
Senior Back-End Engineer
Kilo Health
Scalable health-technology services in a fast-moving consumer healthcare environment.
2023 — 2024
Software Engineer
Notified
Earnings calls and webcasting platform for investor relations. Designed and built APIs across a Python, PHP and TypeScript stack, and became the team's point of contact for security — triaging Dependabot escalations and driving Veracode findings to fixed or mitigated. Set the API standards and mentored the team on the new service.
2022 — 2023
Software Developer
Smartproxy
2021 — 2022
Software Engineer
Oxylabs
High-performance microservices for a web scraping platform, then e-commerce work: dynamic pricing driven by traffic and IP data, Redis-cached APIs, payment webhooks, and a message-queue flow that assigned proxies to clients on successful payment.
2020 — 2021
Software Engineer
Estina
E-commerce functionality, API design and performance work, plus an integration that auto-translated product descriptions across languages.
2018 — 2020
Python & PHP Developer
Genius Sports Group
Competition management systems for football and other sports. RESTful API design and integrations with existing data-collection systems.
2017 — 2018
Python Developer
Visma Lietuva
Building new integrations and migrating existing ones.
2021 — 2024
Teaching & mentoring
Vilnius CODING School · Oxylabs · bit&Byte
Python lecturer, mentor to working developers on OOP, databases, APIs, testing and deployment, and a volunteer mentor teaching technology to 7–14 year olds.
02
Toolbox
Backend
PythonFastAPITypeScriptNode.jsPHPREST APIsMicroservices
Frontend
ReactNext.jsTypeScriptTailwindVite
Data
PostgreSQLMongoDBRedisSQLAlchemyAlembic
Platform
GCPAWSDockerCI/CDVercelGrafanaDatadog
Practice
API securitySAST remediationAutomated testingLLM integrationStripe billing
Certified
AWS Developer – AssociateGCP Core Infrastructure
Languages
English — full professionalLithuanian — nativeRussian — elementary
03
Get in touch
Open to contract work — API and backend builds, integrations, and taking a product from nothing to live. Tell me what you are trying to ship and I will tell you honestly whether I am the right person for it.
arnasgrigaliunas8@gmail.com