Founding Chief Technology Officer (Full-Stack)

Founding Chief Technology Officer (Full-Stack)

Location: Vilnius, Lithuania (office-first; hybrid possible)

Type: Full-time, founder role

About Celper AI

Celper AI builds AI that automates candidate screening and interviewing so teams can hire faster and fairer. Our first product is built and we’re targeting launch in ~1–2 months. We’re talking with early customers and investors. Founding team: two 18-year-old builders who learn fast, move fast, and own mistakes. We’re honest about what we don’t know and do the work to figure it out.

The role

You will be the hands-on founding CTO who owns architecture, codebase, security, and delivery. You’ll turn our product vision into a reliable, scalable product and help translate company goals into clear OKRs. This is a build/lead role: ship now, design for scale, and hire the first engineers once we have traction.

What you’ll do

• Own the stack end-to-end: web app, APIs, data, infra, monitoring, and release process.

• Ship features across the funnel: interview flows, scoring/evaluation, ATS integrations, dashboards.

• Productionize AI: LLM pipelines (prompting + evals/guardrails), voice/video, retrieval/RAG, fallback logic.

• Make it robust: privacy/security by design (GDPR-aware), logging/metrics/tracing, error budgets, cost control.

• Integrations: ATS/webhooks, email/calendar, LinkedIn/CV importers; payments/licensing later.

• Convert company goals into OKRs and deliverables; keep scope tight and momentum high.

• Establish engineering practices: code quality, testing, docs, simple architectures, PR flow.

• Partner with founders on roadmap and customer feedback; interview and onboard future engineers.

What you bring

• Full-stack generalist who has shipped production software end-to-end (startup, indie, or side projects count).

• Backend fundamentals (APIs, data modeling, auth) and modern frontend chops.

• Pragmatic with AI product plumbing: prompting is fine, but you also handle evals, safety, and reliability. You should be able to understand the code and if necessary write it without AI.

• Systems mindset: you design for observability and maintainability from day one.

• Clear communication, bias to action, low ego, high ownership; comfortable working on-site with the team.

• No seniority labels: if you meet these requirements - apply.

We’d love to work with you if you are

• Passionate about AI and excited to turn ideas into shipped, real-world features.

• Energized by building and launching - MVP first, instrument, learn, iterate fast.

• A true team player: you communicate clearly, give/receive feedback, and unblock others.

• Comfortable with ambiguity and constraints; you simplify problems and find leverage.

• Motivated, self-directed, and reliable - you keep promises and own outcomes.

• Curious by default and eager to learn new tools, share knowledge, and help us grow together.

Nice to have (not required)

• HR/ATS domain exposure, B2B SaaS funnels, or handling PII under GDPR/DPAs.

• WebSockets/WebRTC/Twilio, streaming media; vector DBs; LangChain/LlamaIndex experience.

• Early-stage founding experience or a strong desire to be a founder.

We are interested if you have experience across:

Frontend: React/Next.js, TypeScript, Tailwind

Backend: Node/TypeScript (Nest/Fastify) or Python (FastAPI)

Data: Postgres, Redis; vector store (pgvector/Weaviate/Pinecone)

AI: OpenAI/Anthropic, Whisper; retrieval/RAG; prompt pipelines with evals/guardrails

Infra: Docker, CI/CD, Vercel/Fly.io/AWS/GCP; IaC where it helps

Comms: WebSockets

How we work

• Office-first in central Vilnius for speed and learning (preferred on-site).

• Weekly shipping cadence; talk to users; cut scope to hit outcomes.

• We’re young and ambitious; we’ll learn with you. Good vibes mandatory.

Compensation & terms

• All details (including equity and salary) will be discussed during the second phase of the interview process.

Equal opportunity

We care about talent, ethics, and drive. We welcome candidates from all backgrounds who want to build with us.