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vp.Ven Petrov
WorkWritingAboutAt a glance
Software engineer · Barcelona

Hi, I’m Ven.

I build web applications and business software.

I like research. Lately, I’ve been spending a lot of time with LLMs, building voice agents and trying tools like Codex, Claude Code, OpenCode and Pi Agent.

My degree is in business and finance. I’m interested in how the software fits the work people actually need to do.

My path so far GitHub Get in touch
React & Next.jsNode.js & LLM APIsPython & FastAPIERP & business processes
Made with Codex and GPT-6 Astra

I pointed Codex at my project folders and GitHub repositories and asked it to help me build an overview of my work. These pages are the result of that process, with my explanations and corrections along the way. If you want to know more about a project, ask me personally.

A few places to start

Selected projects

All writing
Novartis / financial report explorer54 pages reviewed
+$86mOperating income
Q4 2025 vs Q4 2024
Sales · income · cash flow · balance sheet
Financial review labInteractive prototype

Exploring a financial report with Python and FastAPI

I started with one income change, then opened up the same 54-page report: products, regions, cash flow, core adjustments and a dataset whose figures lead back to the source.

PythonFastAPIReactTypeScript
Explore the working demo
ctxforge / context discoveryBefore implementation
01Ask the missing questions
02Make the scope explicit
03Carry decisions forward
The framework’s intended discovery process.
ctxforgePublic toolkit

ctxforge: discovering what to build before coding

A context discovery framework that asks an LLM to act like a senior engineering interviewer: understand the idea, uncover requirements and agree the scope before an agent starts building.

LLMsContext engineeringNode.jsOpen source
Read the story
Transfutur / internal ERPPHP · MySQL · JavaScript
01
€5–6m in annual invoicingApproximate scale of the business it supported
02
One application, two officesLogistics, administration and accounting tasks
03
Built from zero, supported dailySole engineer through delivery and operation
Transfutur ERPHistorical work

ERP for transport and logistics

As the sole engineer, I built an ERP from zero for transport and logistics. It supported roughly €5–6 million in annual invoicing across two offices, and I kept it running for about a year.

PHPMySQLJavaScriptERP
Read the story
LLM request pathsReact · Express
Input
Product imagesCompare a single call with two steps
01
Vision → descriptionInspect what the first model saw
02
Writing → product copyInspect prompts, usage and cost
Product-description comparison benchLocal comparison prototype

Comparing one model call with separate vision and writing steps

A small product-description tool lets me inspect the visual analysis before the copy is written, change the model used for each step and compare request measurements.

ReactNode.jsOpenAIOpenRouter
Read the story

Loading the writing…

Want to talk about the work?

I’m happy to go through a project, the code behind it or the choices I would revisit.

ven.k.petrov@gmail.com
Ven PetrovSoftware engineer · Barcelona
GitHub ↗LinkedIn ↗Email ↗

Find a project or a note

17 results

Transfutur ERP · ExperienceERP for transport and logisticsAs the sole engineer, I built an ERP from zero for transport and logistics. It supported roughly €5–6 million in annual invoicing across two offices, and I kept it running for about a year.Financial review lab · Project storyExploring a financial report with Python and FastAPII started with one income change, then opened up the same 54-page report: products, regions, cash flow, core adjustments and a dataset whose figures lead back to the source.Crude-oil narrative tracker · Project storyCrude-oil research from global news and market dataI wanted help following global events that could matter for crude oil. The prototype combines news research with calculated market and position values, while keeping recent assessments separate from the longer numeric history.MNQ time-series research · ExperimentTime-series prediction experimentsAn exploration of high-resolution market data: choosing what to acquire, checking its limits, comparing time intervals and testing whether a prediction survived later data and the cost of acting on it.NQ/MNQ backtest engine · Technical noteA missing closing bar left the simulator’s short position openThe strategy reset for a new day while a shared counter still counted yesterday’s short. A small replay shows why closing the position has to happen before clearing its state.Small-cap edge research · Project storyTurning small-cap trading ideas into repeatable researchI asked Claude Code for a fresh research system that could test named price patterns, compare later periods and carry its methodology into new sessions. One candidate shows how features, entry timing and costs fit together.Gadgeon Europe applications · ExperienceConnected-device dashboards and mobile apps at Gadgeon EuropeI worked on Ionic and Angular applications that brought several APIs into dashboards for energy monitoring and connected-device control, with releases and maintenance across multiple client versions.ctxforge · Project storyctxforge: discovering what to build before codingA context discovery framework that asks an LLM to act like a senior engineering interviewer: understand the idea, uncover requirements and agree the scope before an agent starts building.Sociedades Inactivas enquiries · Technical noteSaving an enquiry before trying to send its emailOn the Sociedades Inactivas catalogue, a visitor can ask about a company or send a general enquiry. The form separates saving that request from delivering its notification, including when the visitor retries.Astro local-services website · Project storyA local-services site assembled from city, service and FAQ recordsThe Astro site describes flooring and other local services across different cities. Shared templates check availability, read the matching content and select one FAQ set for both visitors and structured data.3D Spaces website migration · Project storyMoving 3D Spaces to Next.js while its email stayed on the old serverI rebuilt the virtual-tour website with AI coding collaborators, preserving its content and URLs. The cutover also had to protect the mailbox, enquiry flow and existing analytics history.Capture CRM · Project storyConnecting classified listings to contacts in a small CRMA Chrome extension and Next.js dashboard bring classified listings, platform profiles and contact history together. Saving a listing again can add the person who was missing from an earlier import.Product-description comparison bench · ExperimentComparing one model call with separate vision and writing stepsA small product-description tool lets me inspect the visual analysis before the copy is written, change the model used for each step and compare request measurements.Between Us · Project storyBetween Us: why I kept the first take and widened the shotI compared dialogue takes, asked for wider shots and more physical acting, then changed the workflow when its studio limited the scenes I wanted to make.Restaurant-service voice agent · ExperimentDesigning a restaurant-service call around the real offerI worked through a Spanish outbound agent prompt, corrected a free visit to the actual paid service and compared how two drafts handled transfers and bookings.Vapi and Telnyx voice integration · Technical noteThe Vapi agent could speak, but it could not hear me clearlyMy Telnyx number connected to the assistant, but the caller audio was distorted. Three codec tests recovered the connection without fixing that original problem.Warloop: Echoes of Solmara · Project storyWarloop: turning generated character art into a playable prototypeGood-looking character images became tiny figures, a backwards walk and misplaced bosses in the game. I worked through the gap between generated art and playable behavior.
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