Katrina Diaz-Arnold

Katrina Diaz-Arnold – Editor

Developmental editor with 10+ years’ experience (Big Five, NYT bestsellers), focused on fantasy, romance, speculative fiction & thrillers.

Overview

Hello! I’m an experienced developmental and line editor with over ten years of professional publishing experience, and I love helping authors refine their manuscripts into the strongest, most vibrant versions of themselves.

I previously worked as part of the editorial team at Scribner, an imprint of Simon & Schuster, before founding my own editorial services company. Over the course of my career, I’ve had the privilege of working with numerous New York Times and Sunday Times bestselling authors, from debut writers to established voices, across both traditional and independent publishing.

Editing, for me, is both a craft and a calling. I care deeply about the quality of the work and approach every project with respect for both the storytelling and the author behind it. I believe the strongest books emerge through careful attention to authorial intention and constructive editorial guidance. I bring that passion and focus to every project, fully invested in helping each manuscript reach its highest potential.

I have a particular love for brave new worlds, fresh twists, and strong, complex protagonists. I specialize in fantasy, romance (all subgenres), romantasy, thriller (especially espionage), suspense, dystopian and post-apocalyptic fiction, speculative fiction, and YA/NA fantasy and dystopian works.

A passionate, lifelong reader, I hold a BA in Creative Writing from Northwestern University and an MA in Shakespeare from University College London.

Services
Fiction
Contemporary Romance Espionage Historical Romance Paranormal Romance Psychological Thriller Romantic Fantasy Technothriller Young Adult Fantasy
Languages
English (UK) English (US)
Certifications
  • Northwestern University: BA in English in Creative Writing
  • University College London: MA in Shakespeare

Work experience

Self-employed

Jul, 2013 — Present
- Led and managed a team of independent editorial contractors across developmental, line, copy, and proofreading stages prior to publication to ensure consistency and quality control on 75+ projects - Conducted comprehensive editorial assessments and/or in-depth line edits on 200+ manuscripts, improving narrative structure, developmental strength, and market readiness across multiple genres - Collaborated with debut and established authors, including New York Times and Sunday Times bestsellers, across a variety of genres for both standalones and series - Coached authors through ideation, drafting, revisions, and publication or submission strategies - Wrote and edited query letters, synopses, jacket copy, book descriptions, and more - Directed business operations, including strategy, scheduling, budgeting, and contractor management - Specialized in developmental editing, line editing, and writing coaching, addressing big picture concerns related to plot, character, structure, pacing, believability, clarity, and writing style, in genres of fantasy, romance, science fiction, thrillers, and dystopian

Scribner, Simon and Schuster

Jun, 2013 — Sep, 2015 (about 2 years)
- Edited New York Times bestselling and award-winning nonfiction and fiction books for structure, voice, and use of language by completing developmental, line, and copy edits - Wrote promotional copy, book copy, sales tip sheets, editorial letters, and more - Evaluated submissions for publication potential and researches competitive titles - Communicated with writers and agents on a daily basis as the first response to all requests - Managed projects from the onset through to publication, organized publication master schedules, monitored deadlines, payments, and contracts - Strategically solved urgent issues for an average of 25+ projects at any given time - Created original, promotional and/or shareable content for Twitter and Instagram - Supervised minute-taking for editorial meetings and trained all new editorial assistants

Self Employed

Jan, 2013 — Jun, 2013 (5 months)
- Consulted collegiate and postgraduate applicants on personal statements and essays - Wrote marketing copy, brochure copy, and website content for small businesses - Edited manuscripts through developmental edits

Thomson Reuters

Jul, 2012 — Sep, 2012 (2 months)
- Proofread, copyedited, and completed multiple proof checks using BSI Proofing Symbols for legal loose-leaf and book manuscripts from initial copy to the final press proof - Wrote filing instructions, edited checklists, and prepped texts for e-book transitioning

Chalke Authors/Endeavour Press

Nov, 2011 — Jul, 2012 (8 months)
- Copyedited, proofread, and formatted novellas and nonfiction essays for e-book publication - Wrote press releases, inquiry letters, and interview questions - Brainstormed, researched, and implemented two to four publicity campaigns per month

Browne and Miller Literary Associates

Mar, 2011 — Jun, 2011 (3 months)
- Reviewed several manuscripts per week and wrote reader's reports - Managed and responded to all office email and letter queries - Assembled potential proposals for evaluation every two weeks

Portfolio

Made with Reedsy
For Whom the Belle Tolls

Lynn, Jaysea

S&S/Saga Press

Developmental Editing Editorial Assessment
Dark Wine at Midnight (A Hill Vampire Novel)

Barwin, Jenna

Hidden Depths Publishing

Developmental Editing Editorial Assessment
Dark Wine at Sunrise (A Hill Vampire Novel Book 2)

Barwin, Jenna

Hidden Depths Publishing

Developmental Editing Editorial Assessment
Dark Wine at Death (A Hill Vampire Novel Book 4)

Barwin, Jenna

Hidden Depths Publishing

Developmental Editing Editorial Assessment
Made with Reedsy
Between the Shade and the Shadow

Alexander, Coleman

The Realmless, LLC

Editorial Assessment
Made with Reedsy
Night Bloom (Night Bloom Saga Book 1)

Hunsaker, R.G.

Rachel Hunsaker

Developmental Editing
Developmental Editing
Made with Reedsy
The Immundus

Enquist, Christina

Odolf Mingan Publishing

Editorial Assessment
Made with Reedsy
Crimson River (Civilands Book 1)

Austin, N.B.

Moore Bell Productions

Developmental Editing Editorial Assessment
Made with Reedsy
Ez Ozel: Prologue to Perdition

Oliver, Dave

Developmental Editing
Developmental Editing Editorial Assessment
Made with Reedsy
Black Seed (Seed World Book 2)

Marshall, Kenneth

New Athenian

Editorial Assessment
The Last Nazi: a spy thriller (A Joe Johnson Thriller, Book 1)

Turpin, Andrew

The Write Direction Publishing

Developmental Editing Editorial Assessment
Developmental Editing Editorial Assessment
Made with Reedsy
Biohack: A high-tech conspiracy thriller (Shadow Operatives Book 1)

Lasica, J.D.

Best of Indie Publishing

Editorial Assessment
Made with Reedsy
Until I Met Her (Emma Fern, 1)

Barelli, Natalie

Thomas & Mercer

Editorial Assessment
Missing Molly

Barelli, Natalie

The Last Word

Developmental Editing
Woman of the Dead: A Novel

Aichner, Bernhard

Scribner

Editorial Assessment
Developmental Editing
Made with Reedsy
One More Shot: A Caliza County Crime Novel

Laird, Richard

Buckhorn Press

Developmental Editing
Developmental Editing Editorial Assessment
The Ulterior Motive

Coleston, Jack

Everlast Media Group

Developmental Editing
Made with Reedsy
A Lady's Guide to Kiss A Rake

Wilde, Tanya

Developmental Editing
Yuletide Angels (Clan Grant Book 9)

Montclair, Keira

Keira Montclair

Developmental Editing Editorial Assessment
Developmental Editing
Developmental Editing Editorial Assessment
Editorial Assessment
Waiting for December

Costello, Riley

Sullivan & Shea Publishing

Developmental Editing Editorial Assessment
Waiting at Hayden's

Costello, Riley

Sullivan & Shea Publishing

Developmental Editing Editorial Assessment
The Crewmember

Volgyi, Marsha

eXtasy Books

Developmental Editing Editorial Assessment
Made with Reedsy
The Sample Sale Suicide

Verdell, Melanie

Mia Verde LLC

Developmental Editing Editorial Assessment

Katrina has 29 reviews

Professionalism

Quality

Value

Responsiveness

Cary P.

Cary P.

Jul, 2025

Katrina is an amazing editor, and she was the perfect editor for this project! She's easy to work with, and not only did exactly what she said she'd do, but went over and above -- with "extras" that made an already-excellent job better and more helpful. I'd work with her again in a New York-min...
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Jaysea W.

Jaysea W.

Nov, 2024

Katrina was a phenomenal guide for both my developmental and line edits. She was always very communicative, clear, and understanding, and clearly cared about the work she did. I look forward to working with her again!
Jaysea W.

Jaysea W.

Jul, 2024

Katrina has been amazing to work with! As I am a first time author, she was beyond patient in helping me understand various options for editing, as well as wonderfully supportive throughout it all. She has a real passion for what she does, and provided thorough critiques and suggestions to help t...
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J.S. M.

J.S. M.

Jan, 2022

Katrina was willing to make adjustments to her delivery schedule as a result of changes in my travel schedule.
Michelle S.

Michelle S.

Oct, 2021

Katrina is a gifted editor. She gave me the needed content edit for my novel to help me see the big picture and she pointed out (with suggestions) plot, character and voice problems I have been struggling with for a long time. Her edits will guide me to the next stage in the process of completing...
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