Applied AIMachine learningFormer CTO

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Senior / Lead Machine Learning EngineerApplied AIProduction ML Systems

Dr Carl Southall

Senior Machine Learning Engineer and former CTO with a PhD in Deep Learning and 10 years of experience developing and deploying production AI systems across diverse industries and technical domains. Combines extensive expertise in deep learning, generative AI, and multimodal modelling with a proven ability to adapt machine learning techniques to varied challenges and translate research into commercial products. Experienced in end-to-end ML development, cloud architecture, and engineering leadership, including building production systems at Logitech and co-founding an AI-powered startup that secured over £600k in investment.

Co-founded and led an AI-powered startup as CTO
Taking the product from concept to commercial launch, building the engineering team, and raising over £600k in investment.
Delivered production audio ML at Logitech
Developing speech enhancement technologies deployed across thousands of devices in the Rally Bar range. Contributed to the early development and prototyping of Logitech Sight, later recognised as one of TIME's Best Inventions of 2024.
Led the development of cutting-edge AI at Cantine / Phiona
Tackling the most mathematically and technically challenging problems of my career through advanced multimodal learning, generative AI, and psychological modelling.
Combined a passion for music and problem-solving with academic research
Completing a PhD in Audio Engineering and Deep Learning as the youngest person in the lab to earn a doctorate, with 12 research publications across journals, conferences, and workshops.

Experience

  1. Apr 2023 – Present
    Remote

    Co-Founder & CTO

    WithMe

    • Co-founded WithMe, an all-in-one platform for creators, and led engineering from first prototype to a profitable commercial product, helping raise over £600,000 across multiple funding rounds.
    • Designed and built WithMe's AI agent team, a multi-agent system that acts as a back office for each creator. It cut the time to build a creator hub to minutes and saved creators hundreds of hours by automating recurring marketing, sales, support and design work. Otto, a planner agent, delegates tasks to specialist agents (Margo, Sal, Cassie and Dez). The specialists use tools to act on the platform, draw on a shared memory of each creator's brand and audience, and pass key actions to the creator for approval. A feedback system captured creator ratings and edits to refine prompts and evaluation sets.
    • Defined the key product metrics and, through user feedback loops and rapid iteration towards product-market fit, cut monthly churn from 18% to 8% and lifted trial conversion from 32% to 46%.
    • Owned and scaled the full technical architecture across web, mobile, payments, analytics and AI, built on AWS, including a live and recorded video pipeline (IVS, MediaConvert), containerised and serverless back-end services (ECS Fargate, Lambda), and managed data and content delivery (RDS, S3, CloudFront).
    • Hired and mentored a team of three early-career engineers, growing them into engineers who owned production features from design to deployment, through pair programming, code review, CI/CD and shared engineering standards.
  2. Dec 2024 – Feb 2026
    Hybrid, London, United Kingdom

    Lead Audio Machine Learning Engineer

    Cantine / Phiona

    • Led the research and development of deep learning models that infer psychological and behavioural traits from audio. This is a hard problem: labelled data is scarce and labels are subjective, so used self-supervised pre-training and representation learning on large unlabelled audio datasets, then fine-tuned Transformer models on smaller annotated sets.
    • Built multimodal and generative models combining audio with behavioural signals, using GANs and other generative approaches for audio synthesis and data augmentation. Designed the full ML pipeline from data collection and annotation through training, statistical evaluation and benchmarking to production deployment.
    • Conducted applied research with University College London (UCL) across audio ML, generative AI and computational psychology, and built and led a team of three engineers, introducing CI/CD, automated testing and experiment tracking to take research models into production.
  3. Dec 2020 – Apr 2023
    Hybrid, Windsor, United Kingdom

    Senior Audio Machine Learning Engineer

    Logitech

    • Improved the deep learning speech enhancement model running on thousands of Logitech video conferencing devices worldwide, raising audio quality across real-world rooms, noise conditions and languages. The models ran in real time on low-power embedded chips, processing a new audio frame every 10 ms with compute budgets as low as 2 MFLOPS.
    • Led the end-to-end development of a deep learning dereverberation system that improved PESQ by around 1.0, from model architecture and training through hyperparameter optimisation to production deployment, and prototyped early Transformer and convolutional architectures that shaped later production models.
    • Designed and ran large-scale audio dataset collection and annotation across rooms, devices, languages and noise conditions, and built the evaluation framework and objective metrics used to benchmark every speech enhancement and dereverberation model before release.
  4. Jan 2020 – Dec 2020
    Derby, United Kingdom

    Senior Machine Learning Analyst

    Incora / Pattonair

    • Identified new opportunities through top-down analysis and working closely with colleagues, guiding the future direction of the team and business.
    • Delivered a ~£4,000,000 annual working capital reduction by increasing the accuracy of the machine learning forecast engine through new features and more advanced machine learning architectures.
    • Established process, coding, project and testing quality standards across the whole data science team, ensuring high performance output.
  5. May 2019 – Jan 2020
    Manchester, United Kingdom

    Machine Learning Specialist

    Music Tribe

    • Developed the first AI application for live sound audio: Channel AI.
    • Lead author and developer of the in-house machine learning library.
    • Championed and led the team on multiple industry-first machine learning projects.
    • Gathered, processed, stored and utilised large amounts of data.
    • Advanced colleagues' machine learning knowledge through presentations.
  6. Oct 2018 – May 2019
    Birmingham, United Kingdom

    Research Associate / Software Engineer / Machine Learning Engineer

    Semantic Audio Labs Ltd

    • Pioneered all machine learning and deep learning research and products.
    • Delivered seven state-of-the-art machine learning algorithms.
    • Provided expert advice on the future direction of the company.
    • Participated in all project meetings with company leaders and external stakeholders.

Research & education

My PhD focused on deep learning for automatic drum transcription, with work published at ISMIR, DAFx and in IEEE/ACM TASLP.

Publications

Show all 12 publications ↓

Education

  • PhD, Audio Engineering and Deep Learning

    Birmingham City University · 2015–2019

  • Postgraduate Certificate of Research, Audio Engineering and Deep Learning

    Birmingham City University · 2015–2016

  • BSc, Sound Engineering and Production

    Birmingham City University · 2012–2015

    Final year project: Automatic Classification of Drum Sounds using Machine Learning

Awards

  • Doctoral Bursary

    Birmingham City University · 2015

Skills

ML & AI

PyTorchTensorFlowTransformersCNNs/RNNsGANsAutoencodersSelf-supervised & representation learningMultimodal modellingLLM agentsRAGPrompt engineeringModel evaluation

Audio

Speech enhancementDereverberationDSPAcousticsPsychoacousticsReal-time embedded MLAudio dataset collection & annotation

Engineering & cloud

PythonSQLCUDADockerCI/CDAWS (ECS Fargate, Lambda, RDS, S3, CloudFront, IVS)Google CloudDjangoReact/Next.js

Leadership

Technical strategy & roadmapsHiringUniversity research collaboration (UCL)Fundraising support

Strengths

Turning research into productsMentoring engineersProduct & commercial thinkingEnd-to-end ownershipClear technical communication

Outside work

FootballCricketKids, family and friendsTravellingPhilosophyHistoryGamingMusicDrums

Get in touch

I'm always happy to talk about machine learning, audio AI, or building products. The best way to reach me is by email.