Staff backend engineer for high-load data platforms.

12 years on the JVM. Tech lead of a maritime-AI platform that ingests 1M+ sensor metrics a minute from 1,000+ vessels.

or write to windgub@gmail.com

Status
Open to Staff/Lead roles & select freelance projects
Based
Vilnius, Lithuania · EET (UTC+2)
Terms
Fully remote · B2B contract, invoicing from Lithuania (EU)
Scope
Architecture owner · ~25 microservices · design docs · 17 interviews
Stack
Java 21 · Spring Boot · Kafka · PostgreSQL · Redis · AWS
  1. 1,000+ vessels & feeds
    • REST
    • SFTP
    • Azure Data Lake
    • Weather
    • AIS ship tracking
    1M+ metrics / min
  2. KafkaEvent backbone for ~25 Spring Boot microservices~1.4B metrics / day
    • SinkPersists every metric, writes split by category+85% throughput
    • AggregatorOwn input: noon reports and telegrams, aggregated by day and voyage leg6× faster widgets
  3. Time-series DB · PostgreSQL · RedisOn AWS: S3, Lambda, RDS, EC2
    • CII servicesEmission ratings and trends per vessel−10–15% CO₂ (est.)
    • Platform APIInsights and ML model outputs for client dashboards
Figure 1 — The vessel-monitoring platform whose architecture I lead, simplified. Services I built or re-engineered. Linked numbers open the case study.
01

Selected work

  1. +85% throughput, same cloud cost

    +85% pipeline throughput at the same cloud cost

    Re-engineering the service that persists 1M+ sensor metrics a minute. Measure on production-shaped data first, then fix concurrency and write contention.

    Tech lead · load testing, design and implementation · Java 21 · Spring Boot · PostgreSQL

  2. 6× faster key widgets

    6× faster vessel dashboards with a new Aggregator service

    A Java 21 service built from scratch that turns captains' noon reports and telegrams into daily and voyage-leg aggregates, so key widgets read ready answers.

    Designed and built the service from scratch · Java 21 · Spring Boot · PostgreSQL

  3. −10–15% fleet CO₂ (est.); helped retain key clients

    CII emissions tracking that helped keep enterprise clients

    Two Spring Boot services that track vessels' Carbon Intensity Indicator, the IMO rating ship operators are measured on every year.

    Built both services · Java · Spring Boot · PostgreSQL

Table 1 — Results. Each row opens its case study. All case studies →
02

Scope and leadership

Architecture owner, ~25 microservices

I own the architecture of the 1M+ metrics/min data platform and led its platform-wide migration from Java 11 to 21.

Design docs other teams build on

I write the high- and low-level design docs that QA and frontend engineers build and test against, integration contracts and test plans included.

3 mentees, 17 interviews

I mentor junior and mid-level engineers and run technical interviews. At NetCracker I wrote the onboarding exercise every new engineer started with.

JVM-deep, AI-assisted

Deep on the JVM, productive in Node.js and SQL, fluent with AI-assisted development (Claude Code, Copilot, Cursor).

03

Experience

  1. 2022 — now

    Senior Software Engineer / Technical Lead

    DeepSea Technologies (Nabtesco Group) · maritime-AI B2B SaaS · remote

    Most senior engineer on a vessel-monitoring platform of ~25 microservices and technical lead of its 1M+ metrics/min data platform.

    • Java 21
    • Spring Boot
    • Kafka
    • PostgreSQL
    • Time-series DB
    • Redis
    • AWS
  2. 2019 — 2022

    Senior Software Engineer

    3D Issue · digital-publishing SaaS · remote

    Owned features end-to-end across four services of a platform used by publishers such as the Chicago Sun-Times. Took a Node.js service from proof of concept to production; shipped Stripe payments and two-factor auth in the auth gateway.

    • Java 8
    • Spring Boot
    • Node.js
    • MySQL
    • GCP
    • Stripe
  3. 2018 — 2019

    Software Engineer

    SberTech · tech subsidiary of a major banking group · Moscow

    Internal MLOps platform for a bank running ~2,000 ML models: auto-scaling inference on OpenShift, Kafka feature feeds, and the model-metadata registry data scientists used. Migrated a high-volume storage layer from Ignite/GridGain to Oracle.

    • Java
    • Kafka
    • Kubernetes / OpenShift
    • Jenkins
    • Oracle
    • Hibernate
  4. 2014 — 2018

    Software Engineer

    NetCracker Technologies (NEC group) · telecom software · Moscow

    Data-integration framework behind hundreds of daily production flows for AT&T, Orange, Turkcell and NTT Docomo. Sole owner of a service I moved from WebLogic/Oracle to WildFly/PostgreSQL, removing commercial licence costs and cutting deployment time 20%.

    • Java
    • Spring
    • Oracle PL/SQL
    • PostgreSQL
    • WildFly
04

Education

05

Work with me

Hiring a Staff or Lead backend engineer?

I'm looking for a fully remote role on a B2B contract, with real ownership of architecture on data-heavy systems.

or write to windgub@gmail.com

Need senior backend help on a project instead? See freelance and contract work.