Númi Steinn Baldursson
About
Software engineer with experience in distributed systems, machine
learning, and full-stack development. Holds an M.Sc. in Software
Engineering of Distributed Systems from KTH Royal Institute of
Technology, with a thesis on adaptive vector search with formal
guarantees completed with the
Data Systems Lab.
Skills
Software Engineering
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Languages & Tools - Python, Rust, Java, TypeScript,
SQL; Docker, Git, Profiling & Debugging
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Systems & Algorithms - Distributed Systems, HPC,
Scalable System Architecture
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Data & ML - Graph Learning, Data Mining, ML
Pipelines, Large-Scale Data Processing
General
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Core Competencies - Complex Problem Solving,
Collaboration, Autonomy, Adaptability
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Languages - English (Full Professional), Icelandic
(Native), Swedish (Limited Working)
Professional Experience
Sweeply | Reykjavík, Iceland
Backend Software Engineer | 2026–Present
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Architecting a unified property management system integration
framework in TypeScript, with reusable abstractions
for third-party GraphQL, REST, and
webhook integrations.
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Implementing asynchronous message queues, rate limiting, and retry
logic to improve the reliability and scalability of external
integrations.
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Building event-driven backend services with
Google Cloud Pub/Sub,
Cloud Functions, and Firestore;
optimizing data models and access patterns to reduce database costs
and improve operational reliability.
Software Engineer | 2020–2024
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Core developer and early employee contributing to growth from
startup to international clients.
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Built workforce analytics platform using Vue.js,
TypeScript, and Django REST API,
enabling HR teams to analyze global compensation data.
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Developed and optimized pay equity algorithms, ensuring demographic
fairness across up to 500k employee records.
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Delivered scalable front-end and secure REST services for handling
sensitive HR data.
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Led feature development end-to-end in close collaboration with the
product team; occasionally debugged and integrated with existing
Java systems.
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Helped maintain containerized infrastructure using
Docker; supported AWS Lambda-based
analytics, monitored via Sentry, with exposure to
infrastructure management using Pulumi.
Crayon Iceland ehf | Reykjavík, Iceland
Student Assistant / Junior Consultant | 2019
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Supported software asset management audits through data processing
and analysis.
Various Summer/Part-time Jobs
Roles including fisherman, waiter, bartender, landscape construction
foreman | 2011–2019
Education
M.Sc. Software Engineering of Distributed Systems | 2024–June 2026
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Advanced coursework in distributed systems, HPC, scalable ML/AI, and
data intensive computing.
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Achieved highest grade (A) in all courses, demonstrating
consistent top performance.
View course listing
Master Thesis: Reliable & Adaptive Vector Search with the
Data Systems Lab
Project:
Conformal Risk Control for Annoy
Developing a statistical controller that brings rigorous reliability
to approximate nearest-neighbor search with the
Data Systems Lab at KTH. By
framing
Annoy
as a multi-label classification problem and applying
Conformal Prediction, the framework provides formal
guarantees on recall while adaptively minimizing computational cost.
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The Problem: Traditional ANN algorithms are fast
but lack statistical guarantees, often leading to "silent" data
misses in production.
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The Solution: Using
search_k as the
calibration parameter (the number of nodes visited during search),
we apply Conformal Risk Control to find a non-conformity threshold
that guarantees the expected false negative rate is below
α.
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Impact: Enables adaptive search where harder
queries automatically use more computational budget while easier
queries remain fast—all with provable distribution-free guarantees.
Particularly valuable for RAG systems where retrieval
quality directly affects generation quality.
University of Iceland | Reykjavík, Iceland
B.Sc. Software Engineering (First Class with Distinction) | 2017–2020
- Exchange semester at Aarhus University, Spring 2019.
The Commercial College of Iceland | Reykjavík, Iceland
Physics Line | 2012–2016
Select University Projects
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Built a distributed SQL database in
Rust with multiple servers and a client,
demonstrating strong grasp of distributed consensus (OmniPaxos) and
fault tolerance 2025
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Implemented an N-body simulation for high-performance
computing using PyTorch, Dask, and
Cython to analyze computational scaling
2025
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Simulated electromagnetic wave propagation using the FDTD
method, including serial baseline, OpenMP on CPUs,
GPU acceleration, and
MPI domain decomposition
2025
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