Juuso Mittentag

Senior Software Engineer/Backend, Cloud & AI

JuusoMittentag

I build cloud software that manages energy at EV charging sites, from load balancing under grid limits to battery storage and frequency reserve markets. My background is in security, and I’ve worked AI-first since the first Copilot trials.

Get in touch GitHub LinkedIn

Charging site energy · live illustration

FCR-N · balancing

50.000Hz

Reserve response0 kW
Site load / grid limit0 / 600 kW

Charging flexes under the grid connection limit and follows grid frequency as a reserve: FCR-N within ±0.1 Hz of 50 Hz, FCR-D below 49.9 Hz.

5+ years
building backend & cloud systems
BSc Computer Science
First Class Honours, Royal Holloway
Scrum Master
nearly 4 years, agile coach for a team of 8
TS · Rust · Go
core languages, plus Python & C#

Experience

From privileged-access security to energy management for EV charging. Based in Lahti, Finland.

  1. Feb 2023 – nowKempowerSenior since 2026

    Senior Cloud Software Engineer

    Kempower · Lahti, Finland

    Depot & Energy team on ChargEye, Kempower’s cloud charging-management platform, which has recorded 26M+ charging sessions worldwide. Joined as Cloud Software Engineer in 2023, promoted to Senior in 2026.

    • Build cloud services for ChargEye on TypeScript / Node.js and AWS serverless (Lambda, Kinesis, DynamoDB, CloudWatch).
    • Led the work on multiple greenfield energy-management and frequency reserve (FCR) projects for grid reserve market participation, alongside load balancing, charging optimisation and BESS integration.
    • Led the work on North American market compatibility for ChargEye’s load-balancing features.
    • Led ChargEye security audits and the rollout of infosec and code-security tooling.
    • Scrum Master and agile coach of the Depot & Energy team for nearly 4 years, since Feb 2023 (4–8 engineers, currently 8). Built its development processes from scratch.
    • Part of the AI tooling effort from the start: early GitHub Copilot trials, Cursor workshops and evaluations of other AI IDEs and coding agents. Help define AI-assisted workflows for the software unit and work on MCP integrations.
    • TypeScript
    • Node.js
    • AWS Lambda
    • Kinesis
    • DynamoDB
    • FCR
    • Load balancing
    • BESS
    • OCPP
    • OCPI
  2. Aug 2022 – Jan 2023SSH Communications Security

    Junior Backend Developer, PrivX R&D

    SSH Communications Security

    • Built features and architecture improvements for PrivX, a zero-trust privileged access management (PAM) platform, in Go with PostgreSQL and Docker-based microservices.
    • Worked with the UI team on API design and integration, and turned customer requirements into shipped features.
    • Fixed vulnerabilities found by continuous penetration testing. Obtained security clearance for work with highly sensitive information.
    • Go
    • PostgreSQL
    • Docker
    • REST APIs
    • PAM
    • Zero trust
  3. 2020 – 2024BUSR Ltd

    Co-founder & Director of Business Operations

    BUSR · British University Sim Racing

    • Co-founded and scaled a student sim-racing league from a weekend event into official leagues scoring points for the British University Esports Championship.
    • Built the operating structure and secured partnerships with Williams Esports, Alpine F1 Team, The Sim Grid and Monster Energy, which funded the largest winners’ prize in university esports.
    • Founding
    • Partnerships
    • Operations
    • Broadcast production

Selected projects

Things I’ve built outside work, from a full platform to Discord games. One featured, more below.

Featured project

Bunny Sub Tracker

subs.bnuuy.gg · creator, solo full-stack build · 2026

A multi-user analytics platform for Final Fantasy XIV submarine voyages, with an in-game plugin and a Discord bot around it.

  • Rust backend (Loco.rs / Axum, SeaORM, PostgreSQL) and React + TypeScript SPA, with JWT auth, versioned public APIs and CSV / XLSX import-export.
  • C# in-game plugin syncs voyages automatically. A Rust Discord bot posts live fleet boards and stats.
  • Developed AI-first with Claude Code, using agent-oriented architecture docs, project hooks and test-backed workflows.
Visit the site Plugin source

How it fits together

In-game pluginC# · Dalamud
Web appReact · TypeScript
Discord botRust · serenity/poise
Platform APIRust · Loco.rs / Axum · SeaORM · PostgreSQL
  • Hetzner VPS
  • Nginx
  • Cloudflare
  • GitHub Actions CI

Discord game · 2023 – 2026

The Button Bot

A multiplayer waiting game for Discord servers. The longer the shared button goes unpressed, the more points the next press earns, and every press resets the clock for everyone. Configurable scoring curves, multipliers and live scoreboards.

  • Rust
  • poise
  • SeaORM
  • PostgreSQL

Open source · 2025

Ultros contribution

Merged pull request to Ultros, an open-source FFXIV market-data tool: a list summary view that groups prices by data centre and world, with collapsible sections.

  • Rust
  • Open source
View the pull request

Community bots · 2022

Discord bots

Easy QOTD posts a question or poll of the day, with custom question sets, chosen channels and role pings. Sim Signs gave a sim-racing community an April Fools’ horoscope bot.

  • Rust
  • serenity
  • PostgreSQL
More on GitHub

Skills

What I use day to day, grouped by where it shows up.

Languages

  • TypeScript / JavaScript
  • Rust
  • Go
  • Python
  • C#
  • SQL

Backend & web

  • Node.js
  • Express
  • Axum
  • Loco.rs
  • REST API design
  • PostgreSQL
  • DynamoDB
  • React

Cloud & DevOps

  • AWS Lambda
  • Kinesis
  • CloudWatch
  • Serverless
  • Docker
  • GitHub Actions
  • Linux
  • Nginx

AI engineering

  • GitHub Copilot
  • Cursor
  • Claude Code
  • MCP integrations
  • LLM tool calling
  • AI tool evaluation
  • AI workflow design

Energy & EV

  • Energy management
  • Load balancing
  • Frequency reserves (FCR)
  • BESS
  • OCPP
  • OCPI

Security & process

  • Secure SDLC
  • Security audits
  • Code-security tooling
  • PAM
  • Zero trust
  • Scrum Master
  • Agile coaching
  • TDD

Education & languages

BSc (Hons) Computer Science

Royal Holloway, University of London · 2017 – 2020

First Class Honours

Focus on information security, full-stack development and software engineering. Preceded by two years of Geology (2015 – 2017), including computational data analysis.

Languages

Spoken & written

Finnish (native) and English (native).