Invental/ Experts/ Profile
Code reviewArch. reviewArch. design

High-load backend lead for payments and consumer platforms

Best for: seed startup · scale-up · corporate innovation team (especially teams where non-engineers ship with AI tools).

senior / lead backend engineer
online gaming and entertainment, consumer platforms inside messengers, fintech and payments
Kotlin (Spring, Spring Boot, WebFlux, JPA, jOOQ, Flyway), Python, PostgreSQL, Kafka, ClickHouse, BigQuery, Netty WebSockets, GCP / GKE (Kubernetes)
[ M · 01 ]
10
Track-record cases
[ M · 02 ]
3
Scoped reviews you can book with this expert
[ M · 03 ]
6/ 6
Review and architecture services offered
[ M · 04 ]
3
Buyer needs this expert is matched to

§ 01Snapshot

§ 02Services

✓PR/MR code reviewKotlin / JVM, Python backends
✓Architecture review
✓Architecture design
✓Audit / due diligencebackend, infra, cost
✓Vibe-code rescuesafe delivery pipeline first, then backend hardening
✓Team mentoring

§ 03Track record

An isolated CI/CD sandbox so non-technical "vibe coders" can test ideas safely

The marketing team wanted to test product hypotheses themselves, increasingly with AI-generated code, but any change near production was risky.

One of our experts built an isolated CI/CD sandbox: a separate environment and pipeline where non-engineers could deploy and try their ideas, fully cut off from production, while engineering kept trunk-based development on the main line.

Outcome

Marketing could experiment on their own without touching prod, and the engineering team stopped being the bottleneck for every small test.

consumer gaming platform · scale-upGitLab CI, GKE (Kubernetes), Kotlin services, trunk-based development

Proprietary payment services next to highly available third-party gateways

A platform with more than a million monthly users needed in-app payments that kept working when an external provider had a bad day.

One of our experts built the platform's own payment services and integrated third-party payment gateways in a high-availability setup.

Outcome

Payments ran through services the team owned, with external gateways set up so that one failing provider did not stop revenue.

consumer gaming platform · scale-upKotlin, Spring, PostgreSQL, Kafka, JWT

Mitigating large distributed DDoS attacks on a high-traffic API

A public API serving thousands of requests per second was hit by massive distributed attacks.

One of our experts led the backend response: hardening the API layer and the surrounding cloud setup on Kubernetes so attack traffic could be absorbed and filtered.

Outcome

The attacks were mitigated and the platform stayed online for its players.

consumer gaming platform · scale-upKotlin, Netty, GCP / GKE, monitoring

Managed cloud database → self-hosted Postgres on Kubernetes

The managed cloud database was a growing line on the cloud bill and queries were slower than they needed to be.

One of our experts moved the database from the managed service into self-hosted Postgres running in the team's Kubernetes cluster, and took over monitoring of the whole cloud setup.

Outcome

Cloud spend went down and queries got roughly a third faster.

consumer gaming platform · scale-upPostgreSQL, GKE (Kubernetes), GCP

Analytics pipeline from dozens of mini apps, plus warehouse cost tuning

Product analytics had to be collected from dozens of embedded mini apps without slowing the apps down or blowing up warehouse costs.

One of our experts built an event pipeline from Kotlin services through Kafka into a cloud data warehouse, then balanced workloads between the warehouse and a columnar database to control cost.

Outcome

One analytics stream for the whole catalogue, with warehouse spend under control.

consumer gaming platform · scale-upKotlin, Kafka, BigQuery, ClickHouse

A platform engine for dozens of bots with real-time state sync

A messenger-based gaming platform needed one core engine to run dozens of bots and keep game state in sync for players in real time.

One of our experts built the core platform engine that managed the bots, with real-time state synchronisation over WebSockets on Netty.

Outcome

One shared engine powered the platform's bots and live state for a large player base.

messenger-based gaming platform · scale-upKotlin, Netty WebSockets, PostgreSQL, Kafka

Solo migration of a PHP monolith to Kotlin microservices

A mobile game's PHP monolith was holding back development.

One of our experts migrated it alone to Kotlin microservices (Spring Boot, WebFlux, Kafka) on Kubernetes, with trunk-based development and feature toggles so the switch could happen step by step.

Outcome

The product moved to a service architecture without a big-bang rewrite.

mobile game (stock-market themed) · early-stage startupPHP → Kotlin, Spring Boot, WebFlux, Kafka, GKE

Release deploys cut from hours to minutes

Each release took hours of manual deployment work.

One of our experts, working as the DevOps engineer, automated the cloud setup with infrastructure-as-code and custom monitoring metrics.

Outcome

Release deployment went from hours to minutes.

AI trading-analytics SaaS · mid-size SaaSAWS (CloudFormation, Elastic Beanstalk), Nagios custom metrics

Backend for peer-to-peer crypto exchange bots

A peer-to-peer crypto exchange running inside a messenger needed a backend that handled real funds safely.

One of our experts wrote most of the production code: integration with blockchain nodes, hot wallets, and fiat-to-crypto exchange flows in Kotlin/Spring.

Outcome

A working exchange product that moved real money between users.

crypto / P2P exchange · startupKotlin, Spring, blockchain nodes, hot-wallet services

Leading a ten-person cross-functional team with no turnover

A fast-moving platform team (frontend, backend, QA, DevOps) was under constant business pressure.

One of our experts led the team of about ten, ran the technical and management interviews, and acted as a buffer between business demands and the engineers to prevent burnout.

Outcome

The team stayed together; nobody left during their time as lead.

consumer gaming platform · scale-upn/a (leadership), team on Kotlin, React, Angular, GCP

§ 04What you can book

A safe "sandbox + guardrails" setup for a founder who ships with AI

A founder or a non-engineering team generates features with AI tools and deploys straight to production.

Set up a separate sandbox environment and pipeline for experiments, protect the main branch with automated checks, and define how an experiment gets promoted to production after review.

You get

A working sandbox, a written promotion path from experiment to production, and a short list of the riskiest areas in the current backend.

Architecture design · Vibe-code rescueGitLab CI or equivalent, containers / Kubernetes, the product's existing backend

Kotlin / JVM PR review for an AI-assisted backend team

A small team writes much of its Kotlin/Spring code with AI assistants and nobody senior has time to read every PR.

Per-PR review focused on transaction boundaries, payment idempotency, Kafka consumer behaviour, jOOQ/JPA query patterns and migration safety, with comments that explain the why.

You get

Reviewed PRs, plus a short recurring note on patterns the AI keeps getting wrong in this codebase.

PR/MR code review · Team mentoringKotlin, Spring, JPA / jOOQ, Flyway, Kafka, PostgreSQL

Cloud cost and resilience review for a GCP / Kubernetes startup

The cloud bill grows faster than usage and nobody is sure the platform would survive a traffic spike or an attack.

Walk the managed-service bill, database and warehouse workloads, autoscaling and edge protection, and compare self-hosting vs managed for the biggest items.

You get

A prioritised list of cost and resilience fixes, each with its trade-off and rough effort.

Audit / due diligence · Architecture reviewGCP / GKE, PostgreSQL, BigQuery / ClickHouse, monitoring

Questions buyers ask

How can non-technical team members test AI-generated features without risking production?+
Give them an isolated CI/CD sandbox: a separate environment with its own data and deploy pipeline that mirrors production but cannot touch it. One backend lead in our network built exactly this for a marketing team, so hypotheses could be tested freely while production stayed on a trunk-based, reviewed pipeline.
Is it worth moving from a managed cloud database to self-hosted Postgres on Kubernetes?+
It can be when spend is high and the team can own operations. In one case an engineer in our network moved a managed instance into self-hosted Postgres on the cluster, which lowered cloud spend and made queries roughly a third faster; the trade-off is that backups, failover and monitoring become your job.
What should a code review of a payment service check first?+
Idempotency of every money-moving call, what happens when the third-party gateway times out or fails over, and whether retries can double-charge. A reviewer who has run proprietary payment services alongside highly available external gateways looks at these failure paths before style.
How do you protect a consumer API from large DDoS attacks?+
Layer it: edge filtering and rate limits in front, cheap rejection paths in the app, and autoscaling that cannot be weaponised into a cost spike. Our expert has mitigated large distributed attacks against an API serving thousands of requests per second.
— Related experts All experts ↗
CTO-level

M&A due-diligence and high-load architecture CTO

Best for: investors and acquirers · scale-ups with a high-load Java backend · corporate innovation / enterprise R&D teams · founders whose AI-generated codebase has lost its architecture.

Code review, Arch. review +4View profile →
founder-CTO / founding product engineer

0→1 founder-CTO for data-heavy SaaS and agent-ready tooling

Best for: solo founders and seed startups building a data or AI product · SaaS teams adding an API or MCP server · developer-tool companies whose CLI or API will be called by AI agents · founders who want product and engineering advice in one person.

Code review, Arch. review +4View profile →
CTO-level

Continuous-delivery fractional CTO

Best for: solo founders with a vibe-coded MVP · seed startups without a CTO · scale-ups after a funding round · investors needing a quick technical audit · CTOs who want an outside second opinion.

Code review, Arch. review +4View profile →

How it works

  1. Tell us what you need — the repo or system, the question, and the deadline.
  2. We match an expert from the network, with a second reviewer where it helps.
  3. Scoped work, contracted through Invental — review per pull request, a fixed-scope audit or architecture review, or ongoing capacity.

— Invental · software studio · Montevideo, UY

Want this expert on your code?

Tell us what you are building and what you want checked. We confirm the match and the scope before anything starts.

— Get in touch
hi@invental.co ↗
— Or
— What to include

A link or short description of the code or system, what you want checked, your stack, and when you need the answer. No repository access is needed until scope is agreed.

— Or leave a note
We reply within one business day.