# Bitscorp - Small focused senior engineering studio > A small senior engineering team for startups that need it fixed, not staffed. 15+ years building backends, payment systems, and data platforms in Elixir/Phoenix, Ruby/Rails, Go, Python. Senior-led, hands-on — not a staffing agency. Based in Barcelona (CET timezone), working with clients across Europe and remotely worldwide. ## Who Bitscorp is a small focused senior engineering studio led by Alex Korsak (Alexandr Korsak). 15+ years experience. Author of devise_masquerade (552★ Ruby/Rails authentication library). The same team ships the work — no body shop, no staffing agency. Specializes in: - Elixir/Phoenix production systems (hot path extraction, LiveView optimization, Postgres performance) - Data engineering (Airflow, BigQuery, DuckDB, GDPR/PII pipelines) - Full-stack modernization (Python/Ruby → Elixir/Go) - Rescuing AI-built apps (Cursor/Claude projects to production-ready) Location: Barcelona, Spain (CET/CEST timezone) Languages: English, Russian GitHub: https://github.com/oivoodoo LinkedIn: https://www.linkedin.com/in/alexandr-korsak/ ## Starter Packages (fixed-price, this week) ### Phoenix Production Health Check Duration: 5 days Price: €2,400 fixed Read-only review of your Elixir/Phoenix app: slow queries, missing indexes, N+1s, LiveView reconnects, deploy pipeline. Written report + 1–3 fixes merged. What you get: Postgres review (pghero-elixir), Phoenix/LiveView review (N+1s, PubSub), Deploy/ops health check, Written report (10–20 findings), 1–3 fixes merged as PRs, 45-min walkthrough call Details: https://bitscorp.co/ ### Data Pipeline Audit + 1 Fix Duration: 1 week Price: €2,900 fixed Map every source, job, and table. Find the top failure points. Ship one fix (idempotency, alerts). Architecture diagram + ranked backlog. What you get: Map sources, jobs, tables, Find duplicates, schema drift, PII exposure, Cost pass (largest queries), One fix shipped (idempotent pipeline), Architecture diagram, Ranked backlog with estimates Details: https://bitscorp.co/ ### AI-Built App → Production Duration: 2 weeks Price: €5,500 fixed You shipped an MVP with Cursor/Claude. Now you have broken auth, no tests, secrets in the repo. We fix the top risks and get you production-ready. What you get: Security audit (auth, secrets, permissions), Fix top risks (sessions, migrations, jobs), CI + preview deploys, Error tracking & backups, README/runbook, Recorded walkthrough Details: https://bitscorp.co/ ## Services (4-week SKUs and productized offers) ### Full Stack Development Extract one hot path into Elixir or Go. Leave the rest of the company alone. Pricing: Full Stack (4 weeks): €12,000 (50% to start, 50% at week-4 demo. Written SOW required.); Full-stack retainer: €3,000/mo (Monthly in advance, three-month minimum. Capacity for the same class of work, not a blank cheque.) The node that takes the traffic — lobby, matching, payments, fan-out, live board — is still in a request/response stack that was never built for 10k concurrent users. Rewriting the product is a year. Pulling the hot path is a month. Who it's for: SaaS or marketplace with a websocket, queue, or payment path that pages people at peak; A Ruby/Python/Node API that is fine at 500 users and ugly at 10,000; A founder who has already been told “just add Redis” and it did not hold Details: https://bitscorp.co/services/full-stack-development ### AI Consulting A RAG agent on your docs and tickets — not a scripted chatbot. Pricing: Install: €2,500 (100% to start. No handshake work.); Retain: €750/mo (Monthly in advance. Cancel after month 3. Does not include LocaleOps.) Your inbox is full of questions that already have answers in the help center, Notion, or last month’s tickets. A junior cannot drain it. A canned bot makes it worse. AI Consulting reads your corpus and replies with citations, then escalates what it cannot answer. Who it's for: SaaS, ecommerce, or an online school with a real knowledge base; A support lead who can name the ten tickets that repeat every week; A team that will review the first two weeks of answers — not “set and forget” on day one Details: https://bitscorp.co/services/ai-consulting ### App Launch You have a build. We get it through review. We do not build your app. Pricing: Ship: €1,500 (100% to start. One app, iOS + Android. Two clients per month. 20-hour cap.); ASO month: €750 (Monthly in advance. Listing already live. Three clients per month.); Rush (7 days): €2,500 (100% to start. One slot per month. Same deliverable as Ship, compressed.) Vibe-coded and Expo apps die in Preparing for Submission. Certificates, privacy nutrition, Data safety, 6.7" screenshots, a reviewer who needs a test account. You can write the feature. You cannot ship the listing. That is the job. Who it's for: A founder with a TestFlight or an internal AAB and no live store page; An indie who can pay €1,500 and invite us to their ASC — not a student asking for free help; Someone who will not ask us to put the app on Bitscorp’s developer team Details: https://bitscorp.co/services/app-launch ### Data Engineering One pipeline from your events to a warehouse you own, plus a dashboard of metrics you can defend. Pricing: Data Engineering (4 weeks): €12,000 (50% to start, 50% at week-4 demo. Written SOW required.); Analytics retainer: €3,000/mo (Monthly in advance, three-month minimum. Pipeline + dashboard upkeep for the frozen metric list, not a blank cheque for new domains.) DAU lives in three tools and none of them agree. Monday is a CSV. Attribution is a screenshot. You cannot answer which campaign paid back, which cohort stayed, or whether the last release moved retention. A lakehouse programme is a year. A spine — one pipeline, one warehouse, ten metrics — is a month. Who it's for: A mobile, SaaS, or marketplace team with events in Firebase, ads, Mixpanel, or S3 and no warehouse they trust; A founder who can name 5–10 metrics that would change a decision this quarter — not “we need a data team”; Someone who will give source access in week 1 and will not ask us to invent the product strategy from a dashboard Details: https://bitscorp.co/services/data-engineering ### DevOps CI, Kubernetes, rollback, and Prometheus for one product. We do not become your SRE team. Pricing: DevOps (4 weeks): €12,000 (50% to start, 50% at week-4 demo. Written SOW required.); Platform retainer: €3,000/mo (Monthly in advance, three-month minimum. Capacity for the same cluster and pipeline, not a blank cheque for a second product.) Production is SSH and hope. The last deploy has no tag. Rollback is a rumour. There is no dashboard, so the first person who notices an outage is a customer. You do not need a platform org. You need one path that builds, ships, and tells you when it is on fire. Who it's for: A team shipping from a laptop, a fragile GitHub Action, or a single untagged droplet; A founder who will invite us to their cloud account — DigitalOcean, GCP, AWS, or equivalent — and will not ask us to own the billing; Someone who will not ask for 24/7 on-call or a multi-region active-active redesign in the same SOW Details: https://bitscorp.co/services/devops ## Client case studies ### Blastworks In-house big data and analytics platform Designed and built an in-house big data and analytics platform so the team could collect events, process them on AWS, and optimize ad campaigns from owned data. Stack: Go, Kafka, ELK, Amazon EMR, AWS, AWS Spot, Tableau, Metabase, Airflow, Adjust, CleverTap, Leanplum, Ansible, React, Python Details: https://bitscorp.co/case-studies/blastworks Client: https://blastworksinc.com ## Open Source - **devise_masquerade** (552★ on GitHub): Rails authentication extension for admin user impersonation. https://github.com/oivoodoo/devise_masquerade - **phoenix_lens**: Repository analytics dashboard and SQL notebook for Ecto with PII masking. https://github.com/oivoodoo/phoenix_lens - **pghero-elixir**: Postgres performance monitoring for Elixir/Phoenix apps - **phoenix_healthy**: Health check endpoints for Phoenix applications - **redis_poolex**: Redis connection pooling for Elixir GitHub profile: https://github.com/oivoodoo ## Contact Book a 30-min call: https://cal.com/alexandr-korsak-maasgv/30min Email: alex@bitscorp.co Website: https://bitscorp.co Portfolio: https://bitscorp.co/portfolio Team: https://bitscorp.co/team Careers: https://bitscorp.co/careers All services: https://bitscorp.co/services ## Areas Served Europe (primary), remote worldwide Based in Barcelona, Spain Timezone: CET/CEST (UTC+1/+2) --- Full content: https://bitscorp.co/llms-full.txt Sitemap: https://bitscorp.co/sitemap.xml