David Castillo is a veteran music producer, engineer, and mixer whose name has become synonymous with the evolution of modern metal and progressive rock. With a career spanning over two decades, David has carved out a reputation as one of the most sought-after producers in the European metal scene, known both for his meticulous attention to detail and his ability to bring out the emotional core of every performance.

Based in Stockholm, Sweden, David is the founder and head engineer of Ghost Ward and Studio Gröndahl, two of the most revered recording spaces in Northern Europe. These studios have become the creative home for a long list of pioneering bands, attracting artists from around the globe who seek the perfect blend of Scandinavian sonic precision and emotive, genre-pushing production.

David’s production and mixing discography reads like a who’s who of modern heavy music. He is perhaps best known for his longstanding collaboration with Swedish post-metal legends Katatonia, having engineered and co-produced several of their acclaimed releases. His work with bands like Opeth, Leprous, Bloodbath, and Soen has been instrumental in helping those artists refine their evolving sounds, capturing performances that are both brutally heavy and emotionally delicate.

One of the key attributes that sets David apart is his deep musicality. A classically trained musician himself, he approaches his work with a strong understanding of harmony, arrangement, and dynamics. This musical foundation allows David to act not just as a technician, but as a collaborative partner throughout the recording process. Whether he’s tracking intricate vocal harmonies or dialing in the perfect guitar tone, he always seeks to enhance the song as a whole, not just the sound.

In addition to his high-profile album credits, David is also a respected mentor and educator within the production community. Known for his calm, professional demeanor and articulate teaching style, he frequently shares his knowledge through workshops, guest lectures, and behind-the-scenes breakdowns. His sessions are insightful for both newcomers and seasoned engineers, offering valuable perspectives on tone crafting, song structure, and the psychological aspects of recording.

David’s artistic vision is rooted in authenticity and emotion. He believes that the best productions are those that connect with listeners on a deeper level, and he always strives to capture performances that feel honest and unfiltered. This commitment to authenticity, combined with his technical mastery, has earned him the respect of artists and fans alike.

Today, David continues to work with a wide array of artists across genres, always pushing sonic boundaries while maintaining a deep respect for the fundamentals of great songcraft. His presence on Nail The Mix gives members a rare opportunity to learn from one of the most influential and underrated voices in modern music production. Whether you’re an aspiring producer or a seasoned vet, David’s sessions are packed with inspiration and practical techniques that will elevate your craft.